Saffir–Simpson scale

The '''Saffir–Simpson hurricane wind scale''' ('''SSHWS''') is a tropical cyclone intensity scale that classifies hurricanes—which in the Western Hemisphere are tropical cyclones that exceed the intensities of tropical depressions and tropical storms—into five categories distinguished by the intensities of their sustained winds. This measuring system was formerly known as the '''Saffir–Simpson hurricane scale''', or '''SSHS'''.

To be classified as a hurricane, a tropical cyclone must have one-minute-average maximum sustained winds at {{Convert|10|m|ft|abbr=on}} above the surface of at least 74 mph (64 kn, 119 km/h; Category 1).<ref>{{Cite web|url=https://www.nhc.noaa.gov/aboutsshws.php|title=Saffir-Simpson Hurricane Wind Scale|author=|publisher=National Hurricane Center|date=2018|access-date=November 14, 2020}}</ref> The highest classification in the scale, Category 5, consists of storms with sustained winds of at least 157 mph (137 kn, 252 km/h). The classifications can provide some indication of the potential damage and flooding a hurricane will cause upon landfall.

The Saffir–Simpson hurricane wind scale is based on the highest wind speed averaged over a one-minute interval 10 m above the surface. Although the scale shows wind speeds in continuous speed ranges, the US National Hurricane Center and the Central Pacific Hurricane Center assign tropical cyclone intensities in 5-knot (kn) increments (e.g., 100, 105, 110, 115 kn, etc.) because of the inherent uncertainty in estimating the strength of tropical cyclones. Wind speeds in knots are then converted to other units and rounded to the nearest 5 mph or 5 km/h.<ref>{{Cite web|url=https://www.nhc.noaa.gov/pdf/sshws_2012rev.pdf|title=Minor Modification to Saffir-Simpson Hurricane Wind Scale For the 2012 Hurricane Season|author=|publisher=National Hurricane Center|date=2012|access-date=November 14, 2020}}</ref>

The Saffir–Simpson hurricane wind scale is used officially only to describe hurricanes that form in the Atlantic Ocean and northern Pacific Ocean east of the International Date Line. Other areas use different scales to label these storms, which are called ''cyclones'' or ''typhoons,'' depending on the area. These areas (except the JTWC) use ''three-minute'' or ''ten-minute'' averaged winds to determine the maximum sustained wind speed, creating an important difference which frustrates direct comparison between maximum wind speeds of storms measured using the Saffir–Simpson hurricane wind scale (usually 14% more intense) and those measured using a ''ten-minute'' interval (usually 12% less intense).<ref>United States Navy: {{Cite web |url=http://www.nrlmry.navy.mil/~chu/chap6/se200.htm |title=Section 2. Intensity Observations and Forecast Errors |access-date=2008-07-04 |archive-url=https://web.archive.org/web/20070916205204/http://www.nrlmry.navy.mil/~chu/chap6/se200.htm |archive-date=2007-09-16 |url-status=dead |quote=For US Navy interests, the factor 0.88 is used in going from a 1-minute system to a 10-minute system such that TEN-MINUTE MEAN = 0.88 * ONE-MINUTE MEAN or ONE-MINUTE MEAN = 1.14 * TEN-MINUTE MEAN.}} Retrieved on 2018-10-07.</ref>

There is some criticism of the SSHWS for not accounting for rain, storm surge, and other important factors, but SSHWS defenders say that part of the goal of SSHWS is to be straightforward and simple to understand.{{cn|date=April 2025}} There have been proposals for the addition of higher categories to the scale, which would then set a maximum cutoff for Category 5, but none have been adopted {{as of|lc=y|2025|10|df=US}}.

==History== In 1971, the scale was developed by civil engineer Herbert Saffir and meteorologist Robert Simpson, who at the time was director of the U.S. National Hurricane Center (NHC).<ref name="USA Today">{{cite news |author= Williams, Jack | title= Hurricane scale invented to communicate storm danger |work= USA Today |date= May 17, 2005 |access-date= February 25, 2007 | url= https://www.usatoday.com/weather/hurricane/whscale.htm}}</ref> In 1973, the scale was introduced to the general public,<ref name="Bridgeport Post">{{cite news |url= http://www.thehurricanearchive.com/Viewer.aspx?img=82937522_clean&firstvisit=true&src=search&currentResult=9&currentPage=50 |title='73, Hurricanes to be Graded |author=Staff writer |agency= Associated Press |date= May 9, 1973 |access-date= December 8, 2007 |url-status=dead |archive-url=https://web.archive.org/web/20160519155007/http://thehurricanearchive.com/viewer.aspx?currentpage=50&currentresult=9&firstvisit=true&img=82937522_clean&src=search |archive-date= May 19, 2016 }}</ref> and saw widespread use after Neil Frank replaced Simpson at the helm of the NHC in 1974.<ref name="Simpson interview" />

The scale was created by Herbert Saffir, a structural engineer, who in 1969 was commissioned by the United Nations to study low-cost housing in hurricane-prone areas.<ref name=":0">{{cite news |url= https://news.google.com/newspapers?id=TTEfAAAAIBAJ&pg=2625%2C7395281 |archive-url= https://web.archive.org/web/20160417061701/https://news.google.com/newspapers?id=TTEfAAAAIBAJ&sjid=lccEAAAAIBAJ&pg=2625%2C7395281 |url-status= dead |archive-date= April 17, 2016 |title= Hurricanes shaped life of scale inventor |date=August 23, 2001 |author= Press Writer |access-date= March 20, 2016}}</ref> In 1971, while conducting the study, Saffir realized there was no simple scale for describing the likely effects of a hurricane.<ref name=":1">{{Cite journal |last1=Saffir |first1=Herbert S. |last2=P.e. |first2=F. Asce |date=1983-05-01 |title=Practical aspects of design for hurricane-resistant structures; wind loadings |url=https://www.sciencedirect.com/science/article/abs/pii/0167610583901046 |journal=Journal of Wind Engineering and Industrial Aerodynamics |volume=11 |issue=1 |pages=247–259 |doi=10.1016/0167-6105(83)90104-6 |bibcode=1983JWEIA..11..247S |issn=0167-6105 |archive-url=https://web.archive.org/web/20241006000000/https://www.sciencedirect.com/science/article/abs/pii/0167610583901046 |archive-date=2024-10-06|url-access=subscription }} [https://archive.org/details/0167-6105-2883-2990104-6 Alt URL]</ref> By using subjective damage-based scales for earthquake intensity like the Modified Mercalli intensity scale or MSK-64 intensity scale and the objective numerical gradation method of the Richter scale as models, he proposed a simplified 1–5 grading scale as a guide for areas that do not have hurricane building codes. The grades were based on two main factors: objective wind gust speeds sustaining for 2–3 seconds at an elevation of 9.2 meters, and subjective levels of structural damage.<ref name=":1" /><ref name=":2">{{UN doc|docid=ST/ESA/23|body=Secretariat, Department of Economic and Social Affairs|type=D|resolution_number=|document_number=|title=Low-cost construction resistant to earthquakes and hurricanes|date=31/12/1974|year=1974|language=English|pages=14-20;159-160}}</ref> {| class="wikitable" |+Proposed Hurricane Damage Scale (UN 1974)<ref name=":2" /> |'''Grade''' |'''Wind Speed Range''' |- |Grade 1 |120–150 km/h |- |Grade 2 |151–180 km/h |- |Grade 3 |181–210 km/h |- |Grade 4 |211–240 km/h |- |Grade 5 |241+ km/h |}

Saffir gave the proposed scale to the NHC for their use, where Simpson changed the terminology from "grade" to "category", organized them by sustained wind speeds of 1 minute duration, and added storm surge height ranges, adding barometric pressure ranges later on. In 1975, the Saffir–Simpson Scale was first published publicly.<ref name="Simpson interview" /><ref name=":1" /><ref>{{Cite web |title=Saffir-Simpson Hurricane Scale (U.S. National Park Service) |url=https://www.nps.gov/articles/saffir-simpson-hurricane-scale.htm |access-date=2024-10-06 |website=www.nps.gov |language=en}}</ref>

In 2009, the NHC eliminated pressure and storm surge ranges from the categories, transforming it into a pure wind scale, called the Saffir–Simpson Hurricane Wind Scale (Experimental) [SSHWS].<ref name="NHC SSHS">[http://www.nhc.noaa.gov/aboutsshws.php The Saffir–Simpson Hurricane Wind Scale ''National Hurricane Center''. Accessed 2009-05-15.]</ref> The updated scale became operational on May 15, 2010.<ref>[http://www.ofcm.gov/nhop/10/pdf/2010%20NHOP%20entire%20document.pdf National Hurricane Operations Plan] {{webarchive|url=https://web.archive.org/web/20110708201653/http://www.ofcm.gov/nhop/10/pdf/2010%20NHOP%20entire%20document.pdf |date=July 8, 2011 }}, NOAA. Accessed July 3, 2010.</ref> The scale excludes flood ranges, storm surge estimations, rainfall, and location, which means a Category 2 hurricane that hits a major city will likely do far more cumulative damage than a Category 5 hurricane that hits a rural area.<ref name="LiveScience"/> The agency cited examples of hurricanes as reasons for removing "scientifically inaccurate" information, including Hurricane Katrina (2005) and Hurricane Ike (2008), which both had stronger than estimated storm surges, and Hurricane Charley (2004), which had weaker than estimated storm surge.<ref>{{cite web |url= http://www.weather.gov/infoservicechanges/sshws.pdf |title= Experimental Saffir–Simpson Hurricane Wind Scale |year= 2009 |publisher= National Hurricane Center |access-date= August 17, 2009 |archive-url= https://web.archive.org/web/20090806142811/http://www.weather.gov/infoservicechanges/sshws.pdf |archive-date= August 6, 2009 |url-status= dead }}</ref> Since being removed from the Saffir–Simpson hurricane wind scale, storm surge prediction and modeling is handled by computer numerical models such as ADCIRC and SLOSH.

In 2012, the NHC extended the wind speed range for Category 4 by 1 mph in both directions, to 130–156 mph, with corresponding changes in the other units (113–136 kn, 209–251 km/h), instead of 131–155 mph (114–135 kn, 210–249 km/h). The NHC and the Central Pacific Hurricane Center assign tropical cyclone intensities in 5 knot increments, and then convert to mph and km/h with a similar rounding for other reports. So an intensity of 115 kn is rated Category 4, but the conversion to miles per hour (132.3 mph) would round down to 130 mph, making it appear to be a Category 3 storm. Likewise, an intensity of 135 kn (~155 mph, and thus Category 4) is 250.02 km/h, which, according to the definition used before the change would be Category 5.<ref name="NHC SSHS" />

To resolve these issues, the NHC had been obliged to incorrectly report storms with wind speeds of 115 kn as 135 mph, and 135 kn as 245 km/h. The change in definition allows storms of 115 kn to be correctly rounded down to 130 mph, and storms of 135 kn to be correctly reported as 250 km/h, and still qualify as Category 4. Since the NHC had previously rounded incorrectly to keep storms in Category 4 in each unit of measure, the change does not affect the classification of storms from previous years.<ref name="NHC SSHS" /> The new scale became operational on May 15, 2012.<ref>[http://www.nhc.noaa.gov/news/20120301_pis_sshws.php Public Information Statement], NOAA. Accessed March 9, 2012.</ref>

==Categories== The scale separates hurricanes into five different categories based on wind. The U.S. National Hurricane Center classifies hurricanes of Category 3 and above as ''major hurricanes''. The Joint Typhoon Warning Center classifies typhoons of 150 mph (240 km/h) or greater (strong Category 4 and Category 5) as ''super typhoons''. Most weather agencies use the definition for sustained winds recommended by the World Meteorological Organization (WMO), which specifies measuring winds at a height of {{convert|33|ft|m|1|abbr=on}} for 10 minutes, and then taking the average. By contrast, the U.S. National Weather Service, Central Pacific Hurricane Center and the Joint Typhoon Warning Center define sustained winds as average winds over a period of one minute, measured at the same {{convert|33|ft|m|1|abbr=on}} height,<ref name="NWSM Defs">{{cite web | author = Tropical Cyclone Weather Services Program | title = Tropical cyclone definitions | url = http://www.weather.gov/directives/sym/pd01006004curr.pdf | date = June 1, 2006 | access-date = November 30, 2006 | publisher = National Weather Service}}</ref><ref name="FEMA glossary">{{cite web | author=Federal Emergency Management Agency | title = Hurricane Glossary of Terms | year = 2004 | access-date = March 24, 2006 | url = http://www.fema.gov/hazards/hurricanes/hurglos.shtm |archive-url = https://web.archive.org/web/20051214034332/http://www.fema.gov/hazards/hurricanes/hurglos.shtm |archive-date = December 14, 2005}} Accessed through the Wayback Machine.</ref> and that is the definition used for this scale.

The five categories are described in the following subsections, in order of increasing intensity.<ref>{{Cite news|url=https://www.livescience.com/33668-hurricane-famous-examples-5-hurricane-categories.html|title=Name That Hurricane: Famous Examples of the 5 Hurricane Categories|work=Live Science|access-date=September 11, 2017}}</ref> Example hurricanes for each category are limited to those which made landfall at their maximum achieved category on the scale.

===Category 1=== {{See also|List of Category 1 Atlantic hurricanes|List of Category 1 Pacific hurricanes}} {| class="wikitable" style="text-align: center; float:right; margin-left: 1em; width:350px;" ! style="background: #{{Storm colour|cat1}}; text-align: center;" colspan="2" | Category 1 |- ! Sustained winds ! Most recent landfall |- | 33–42 m/s 64–82 kn 119–153 km/h 74–95 mph | style = "font-size: 80%; width:142px" |140px Oscar in 2024 at landfall in Cuba |}

'''''Very dangerous winds will produce some damage'''''

Category 1 storms usually cause no significant structural damage to most well-constructed permanent structures. They can topple unanchored mobile homes, as well as uproot or snap weak trees. Poorly attached roof shingles or tiles can blow off. Coastal flooding and pier damage are often associated with Category 1 storms. Power outages are typically widespread to extensive, sometimes lasting several days. Even though it is the least intense type of hurricane, they can still produce widespread damage and can be life-threatening storms.<ref name="NHC SSHS"/>

Hurricanes that peaked at Category 1 intensity and made landfall at that intensity include: Juan (1985), Ismael (1995), Danny (1997), Stan (2005), Humberto (2007), Isaac (2012), Manuel (2013), Earl (2016), Newton (2016), Nate (2017), Barry (2019), Lorena (2019), Hanna (2020), Isaias (2020), Nicholas (2021), Pamela (2021), Julia (2022), Lisa (2022), Nicole (2022), Debby (2024), and Oscar (2024). {{Clear}}

===Category 2=== {{see also|List of Category 2 Atlantic hurricanes|List of Category 2 Pacific hurricanes}} {| class="wikitable" style="text-align: center; float:right; margin-left: 1em; width:350px;" ! style="background: #{{Storm colour|cat2}}; text-align: center;" colspan="2" | Category 2 |- ! Sustained winds ! Most recent landfall |- | 43–49 m/s 83–95 kn 154–177 km/h 96–110 mph | style = "font-size: 80%; width:142px" |140px Francine in 2024 at landfall near Morgan City, Louisiana |}

'''''Extremely dangerous winds will cause extensive damage'''''

Storms of Category 2 intensity often damage roofing material, sometimes exposing the roof, and inflict damage upon poorly constructed doors and windows. Poorly constructed signs and piers can receive considerable damage and many trees are uprooted or snapped. Mobile homes, whether anchored or not, are typically damaged and sometimes destroyed, and many manufactured homes suffer structural damage. Small craft in unprotected anchorages may break their moorings. Extensive to near-total power outages and scattered loss of potable water are likely, possibly lasting many days.<ref name="NHC SSHS"/>

Hurricanes that peaked at Category 2 intensity and made landfall at that intensity include: Alice (1954), Ella (1958), Ginny (1963), Fifi (1974), Diana (1990), Gert (1993), Rosa (1994), Erin (1995), Henriette (1995), Alma (1996), Marty (2003), Juan (2003), Alex (2010), Tomas (2010), Carlotta (2012), Arthur (2014), Sally (2020), Olaf (2021), Rick (2021), Agatha (2022), and Francine (2024). {{Clear}}

=== Category 3 ===

{{See also|List of Category 3 Atlantic hurricanes|List of Category 3 Pacific hurricanes}} {| class="wikitable" style="text-align: center; float:right; margin-left: 1em; width:350px;" ! style="background: #{{Storm colour|cat3}}; text-align: center;" colspan="2" | Category 3 |- ! Sustained winds ! Most recent landfall |- | 50–58 m/s 96–112 kn 178–208 km/h 111–129 mph | style = "font-size: 80%; width:142px" | 140px Rafael in 2024 just prior to its landfall in Cuba |}

'''''Devastating damage will occur'''''

Tropical cyclones of Category 3 and higher are described as ''major hurricanes'' in the Atlantic, Eastern Pacific, and Central Pacific basins. These storms can cause some structural damage to small residences and utility buildings, particularly those of wood frame or manufactured materials with minor curtain wall failures. Buildings that lack a solid foundation, such as mobile homes, are usually destroyed, and gable-end roofs are peeled off.<ref name="NHC SSHS"/>

Manufactured homes usually sustain severe and irreparable damage. Flooding near the coast destroys smaller structures, while larger structures are struck by floating debris. A large number of trees are uprooted or snapped, isolating many areas. Terrain may be flooded well inland. Near-total to total power loss is likely for up to several weeks. Home water access will likely be lost or contaminated.<ref name="NHC SSHS"/>

Hurricanes that peaked at Category 3 intensity and made landfall at that intensity include: Easy (1950), Carol (1954), Hilda (1955), Audrey (1957), Olivia (1967), Ella (1970), Eloise (1975), Alicia (1983), Elena (1985), Kiko (1989), Roxanne (1995), Fran (1996), Isidore (2002), Jeanne (2004), Lane (2006), Karl (2010), Otto (2016), Zeta (2020), Grace (2021), John (2024), and Rafael (2024). {{Clear}}

===Category 4=== {{See also|List of Category 4 Atlantic hurricanes|List of Category 4 Pacific hurricanes}} {| class="wikitable" style="text-align: center; float:right; margin-left: 1em; width:350px;" ! style="background: #{{Storm colour|cat4}}; text-align: center;" colspan="2" | Category 4 |- ! Sustained winds ! Most recent landfall |- | 58–70 m/s 113–136 kn 209–251 km/h 130–156 mph | style="font-size: 80%; width:142px" | 140px Helene in 2024 just prior to its Florida Big Bend landfall |}

'''''Catastrophic damage will occur'''''

Category 4 hurricanes tend to produce more extensive curtainwall failures, with some complete structural failure on small residences. Heavy, irreparable damage and near-complete destruction of gas station canopies and other wide span overhang type structures are common. Mobile and manufactured homes are often flattened. Most trees, except for the hardiest, are uprooted or snapped, isolating many areas. These storms cause extensive beach erosion. Terrain may be flooded far inland. Total and long-lived electrical and water losses are to be expected, possibly for many weeks.<ref name="NHC SSHS"/>

The 1900 Galveston hurricane, the deadliest natural disaster to hit the United States, peaked at an intensity that corresponds to a modern-day Category 4 storm. Other examples of storms that peaked at Category 4 intensity and made landfall at that intensity include: Hazel (1954), Gracie (1959), Donna (1960), Carla (1961), Flora (1963), Betsy (1965), Celia (1970), Carmen (1974), Madeline (1976), Frederic (1979), Joan (1988), Iniki (1992), Charley (2004), Dennis (2005), Ike (2008), Harvey (2017), Laura (2020), Eta (2020), Ida (2021), Lidia (2023), and Helene (2024). {{Clear}}

===Category 5=== {{See also|List of Category 5 Atlantic hurricanes|List of Category 5 Pacific hurricanes}} {| class="wikitable" style="text-align: center; float:right; margin-left: 1em; width:350px;" ! style="background: #{{Storm colour|cat5}}; text-align: center;" colspan="2" | Category 5 |- ! Sustained winds ! Most recent landfall |- | ≥ 70 m/s ≥ 137 kn ≥ 252 km/h ≥ 157 mph | style = "font-size: 80%; width:142px" |frameless|199x199px Melissa in 2025 at its record peak intensity before making landfall in Jamaica |}

'''''Catastrophic damage will occur'''''

Category 5 is the highest category of the Saffir–Simpson scale. These storms cause complete roof failure on many residences and industrial buildings, and some complete building failures with small utility buildings blown over or away. The collapse of many wide-span roofs and walls, especially those with no interior supports, is common. Very heavy and irreparable damage to many wood-frame structures and total destruction to mobile/manufactured homes is prevalent.<ref name="NHC SSHS"/>

Only a few types of structures are capable of surviving intact, and only if located at least {{convert|3|to|5|mi|km|0}} inland. They include office, condominium and apartment buildings and hotels that are of solid concrete or steel frame construction, multi-story concrete parking garages, and residences that are made of either reinforced brick or concrete/cement block and have hipped roofs with slopes of no less than 35 degrees from horizontal and no overhangs of any kind, and if the windows are either made of hurricane-resistant safety glass or covered with shutters. Unless most of these requirements are met, the catastrophic destruction of a structure may occur.<ref name="NHC SSHS"/>

The storm's flooding causes major damage to the lower floors of all structures near the shoreline. Many coastal structures can be completely flattened or washed away by the storm surge. Virtually all trees are uprooted or snapped and some may be debarked, isolating most affected communities. Massive evacuation of residential areas may be required if the hurricane threatens populated areas. Total and extremely long-lived power outages and water losses are to be expected, possibly for up to several months.<ref name="NHC SSHS"/>

Historical examples of storms that made landfall at Category 5 status include: "Cuba" (1924), "Okeechobee" (1928), "Bahamas" (1932), "Cuba–Brownsville" (1933), "Labor Day" (1935), Janet (1955), Inez (1966), Camille (1969), Edith (1971), Anita (1977), David (1979), Gilbert (1988), Andrew (1992), Dean (2007), Felix (2007), Irma (2017),<ref>{{Cite web|url=http://www.crh.noaa.gov/Image/mkx/pdf/handouts/famous-hurricanes.pdf|title=Famous Hurricanes of the 20th and 21st Century in the United States|website=www.weather.gov/crh/}}</ref> Maria (2017),<ref name="auto">{{cite report|first=Eric|last=Blake|publisher=National Hurricane Center|location=Miami, Florida|date=September 20, 2017|access-date=September 20, 2017|title=Hurricane Maria Tropical Cyclone Update|url=http://www.nhc.noaa.gov/archive/2017/al15/al152017.update.09200759.shtml}}</ref> Michael (2018),<ref name="michael tcr">{{cite tech report|author=John L. Beven II|author2=Robbie Berg|author3=Andrew Hagen|publisher=National Hurricane Center|date=April 19, 2019|access-date=April 19, 2019|title=Tropical Cyclone Report: Hurricane Michael|url=https://www.nhc.noaa.gov/data/tcr/AL142018_Michael.pdf}}</ref> Dorian (2019), Otis (2023; the only Pacific hurricane to make landfall at Category 5 intensity), and Melissa (2025).

==Criticism== Some scientists, including Kerry Emanuel and Lakshmi Kantha, have criticized the scale as being too simplistic, namely that the scale takes into account neither the physical size of a storm nor the amount of precipitation it produces.<ref name="LiveScience"/> They and others point out that the Saffir–Simpson scale, unlike the moment magnitude scale used to measure earthquakes, is not continuous, and is quantized into a small number of categories. Proposed replacement classifications include the Hurricane Intensity Index, which is based on the dynamic pressure caused by a storm's winds, and the Hurricane Hazard Index, which is based on surface wind speeds, the radius of maximum winds of the storm, and its translational velocity.<ref name="Kantha HHI HII">{{cite journal | author = Kantha, L. | date = January 2006 | title = Time to Replace the Saffir–Simpson Hurricane Scale? | journal = Eos | volume = 87 | issue = 1 | pages = 3, 6 | doi = 10.1029/2006eo010003 | bibcode = 2006EOSTr..87....3K | doi-access = free }}</ref><ref name="Kantha BAMS">{{cite journal|last=Kantha|first=Lakshmi|date=February 2008|title=Tropical Cyclone Destructive Potential by Integrated Kinetic Energy|journal=Bulletin of the American Meteorological Society|volume=89|issue=2|pages=219–221|doi=10.1175/BAMS-89-2-219|bibcode = 2008BAMS...89..219K |citeseerx=10.1.1.693.5083}}</ref> Both of these scales are continuous, akin to the Richter scale.<ref name="UCL alternates">{{cite web | author = Benfield Hazard Research Centre | publisher = University College London | title = Atmospheric Hazards | work = Hazard & Risk Science Review 2006 | url = http://www.benfieldhrc.org/activities/hrsr/h&rsr_2006/atmospheric.htm | year = 2006 | access-date = December 8, 2007 | archive-url = https://web.archive.org/web/20080807165607/http://www.benfieldhrc.org/activities/hrsr/h%26rsr_2006/atmospheric.htm | archive-date = August 7, 2008 | url-status = dead | df = dmy-all }}</ref> However, neither of these scales has been used by officials.{{cn|date=February 2021}}

===Proposed extensions=== After the series of powerful storm systems of the 2005 Atlantic hurricane season, as well as after Hurricane Patricia, a few newspaper columnists and scientists brought up the suggestion of introducing Category 6. They have suggested pegging Category 6 to storms with winds greater than {{convert|174|or|180|mph|m/s kn km/h|abbr=on}}.<ref name="LiveScience">{{cite news|author = Ker Than|title = Wilma's Rage Suggests New Hurricane Categories Needed|work= LiveScience|date = October 20, 2005|url = http://www.livescience.com/environment/051020_hurricane_winds.html|access-date = October 20, 2005}}</ref><ref>{{cite news | author=Bill Blakemore | title=Category 6 Hurricanes? They've Happened: Global Warming Winds Up Hurricane Scientists as NOAA Issues Its Atlantic Hurricane Predictions for Summer 2006 | publisher=ABC News | date=May 21, 2006 | url=https://abcnews.go.com/US/Science/story?id=1986862&page=1 | access-date=September 10, 2006}}</ref> Fresh calls were made for consideration of the issue after Hurricane Irma in 2017,<ref>{{cite web|url=https://www.cbsnews.com/news/climate-scientists-mull-category-six-storm-classification-report-says/ |title=Climate scientists mull Category 6 storm classification, report says |publisher=ABC News|date=February 22, 2018}}</ref> which was the subject of a number of seemingly credible false news reports as a "Category 6" storm,<ref>{{cite news|url=https://www.express.co.uk/news/weird/850253/Hurricane-Irma-NOAA-hurricane-category-6-Irma-path |title=Hurricane Irma: Will Irma become world's first CATEGORY 6 hurricane with 200mph winds? |newspaper=Daily Express|date=September 5, 2017}}</ref> partly in consequence of so many local politicians using the term. Only a few storms of this intensity have been recorded.

Of the 45 hurricanes currently considered to have attained Category 5 status in the Atlantic, 20 had wind speeds at {{convert|175|mph|m/s kn km/h|abbr=on}} or greater. Only 10 had wind speeds at {{convert|180|mph|m/s kn km/h|abbr=on|sigfig=3}} or greater (the 1935 Labor Day hurricane, Allen, Gilbert, Mitch, Rita, Wilma, Irma, Dorian, Milton, and Melissa). Of the 21 hurricanes currently considered to have attained Category 5 status in the eastern Pacific, only 5 had wind speeds at {{convert|175|mph|m/s kn km/h|abbr=on}} or greater (Patsy, John, Linda, Rick, and Patricia). Only 3 had wind speeds at {{convert|180|mph|m/s kn km/h|abbr=on|sigfig=3}} or greater (Linda, Rick, and Patricia).

Most storms which would be eligible for this category were typhoons in the western Pacific, where the scale is not officially used, most notably typhoons Tip, Halong, Mawar, and Bolaven in 1979, 2019 and 2023 (2 storms) respectively, each with sustained winds of {{convert|190|mph|km/h|abbr=on|round=5}},<ref>{{cite web |author=Debi Iacovelli and Tim Vasquez |year=1998 |title=Supertyphoon Tip: Shattering all records |work=Monthly Weather Log |access-date=September 19, 2010 |url=http://www.vos.noaa.gov/MWL/aug1998.pdf |publisher=National Oceanic and Atmospheric Administration}}</ref> and typhoons Haiyan, Meranti, Goni, and Surigae in 2013, 2016, 2020 and 2021 respectively, each with sustained winds of {{convert|195|mph|km/h|abbr=on|round=5}}.

Occasionally, suggestions of using even higher wind speeds as the cutoff have been made. In a newspaper article published in November 2018, NOAA research scientist Jim Kossin said that the potential for more intense hurricanes was increasing as the climate warmed, and suggested that Category 6 would begin at {{Convert|195|mph|m/s kn km/h|abbr=on|round=5}}, with a further hypothetical Category 7 beginning at {{Convert|230|mph|m/s kn km/h|abbr=on|round=5}}.<ref>{{Cite news|url=https://www.tampabay.com/weather/category-6-scientists-warn-hurricanes-could-keep-getting-stronger-20181130/|title=Category 6? Scientists warn hurricanes could keep getting stronger|date=2018-11-30|work=Tampa Bay Times|access-date=2018-11-30|language=en}}</ref> In 2024 another proposal to add "Category 6" was made, with a minimum wind speed of {{convert|192|mph|km/h|abbr=on}}, with risk factors such as the effects of climate change and warming ocean temperatures part of that research.<ref>{{Cite news|title=The growing inadequacy of an open-ended Saffir–Simpson hurricane wind scale in a warming world|work=PNAS|date=2024 |doi=10.1073/pnas.2308901121 |last1=Wehner |first1=Michael F. |last2=Kossin |first2=James P. |volume=121 |issue=7 |article-number=e2308901121 |doi-access=free }}</ref> In the NHC area of responsibility, only Patricia had winds greater than {{convert|190|mph|m/s kn km/h|abbr=on|round=5}}.

According to Robert Simpson, co-creator of the scale, there are no reasons for a Category 6 on the Saffir–Simpson scale because it is designed to measure the potential damage of a hurricane to human-made structures. Simpson explained that "... when you get up into winds in excess of {{convert|155|mph|km/h|abbr=on}} you have enough damage if that extreme wind sustains itself for as much as six seconds on a building it's going to cause rupturing damages that are serious no matter how well it's engineered."<ref name="Simpson interview">{{cite news |author=Debi Iacovelli |title=The Saffir/Simpson Hurricane Scale: An Interview with Dr. Robert Simpson |newspaper=Sun-Sentinel |location=Fort Lauderdale, FL |date=July 2001 |url=http://www.novalynx.com/simpson-interview.html |access-date=September 10, 2006 |archive-url=https://web.archive.org/web/20091023063932/http://www.novalynx.com/simpson-interview.html |archive-date=October 23, 2009 |url-status=dead }}</ref> Nonetheless, the counties of Broward and Miami-Dade in Florida have building codes which require that critical infrastructure buildings be able to withstand Category 5 winds.<ref name="Irma could test strength of Florida's strict building codes">{{cite news |author=Jennifer Kay |title=Irma could test strength of Florida's strict building codes |newspaper=The Washington Post |location=Washington, DC |date=September 2017 |url=https://www.washingtonpost.com/business/irma-could-test-strength-of-floridas-strict-building-codes/2017/09/07/cc82f8f4-9413-11e7-8482-8dc9a7af29f9_story.html |archive-url=https://web.archive.org/web/20170917033507/https://www.washingtonpost.com/business/irma-could-test-strength-of-floridas-strict-building-codes/2017/09/07/cc82f8f4-9413-11e7-8482-8dc9a7af29f9_story.html |url-status=dead |archive-date=2017-09-17 |access-date=September 16, 2017}}</ref>

New proposed scales include those based on factors other than peak wind speed alone. One proposal involves separate scales for wind, for storm surge, and for rainfall.<ref name=USAtoday_20260420/> Another involves a combination of storm surge, rainfall, and wind.<ref name=USAtoday_20260420/> A further proposal focuses on "central pressure deficit"—the difference in barometric pressure between the center of the storm and outside it—as an overall intensity metric correlating better with damage and being easier to measure.<ref name=USAtoday_20260420>{{cite news |last1=Rice |first1=Doyle |last2=Pulver |first2=Dinah Voyles |title=Is Category 5 the worst type of hurricane? Absolutely not. |url=https://www.usatoday.com/story/news/weather/2026/04/20/hurricane-categories-saffir-simpson-scale/89609985007/ |work=USA Today |date=20 April 2026 |archive-url=https://web.archive.org/web/20260420173903/https://www.usatoday.com/story/news/weather/2026/04/20/hurricane-categories-saffir-simpson-scale/89609985007/ |archive-date=20 April 2026 |url-status=live}}</ref>

==See also== {{Portal|Tropical cyclones}} * Beaufort scale{{snd}}Relates wind speed to observable conditions at sea and on land * Enhanced Fujita scale – For tornado intensity with damage correlated to wind speeds. The system was also intended for applicability in hurricanes, and is utilized by engineers in hurricane damage assessment. * Hurricane engineering * Hypercane * Outline of tropical cyclones * Rohn emergency scale for measuring the magnitude (intensity) of any emergency

==References== {{Reflist}}

==External links== * [http://www.nhc.noaa.gov/aboutsshws.php Saffir–Simpson Hurricane Wind Scale]—U.S. National Hurricane Center * {{Cite news |title=An Interview with Dr. Robert Simpson |url=http://www.novalynx.com/simpson-interview.html |archive-url=https://web.archive.org/web/20091023063932/http://www.novalynx.com/simpson-interview.html |archive-date=October 23, 2009 |url-status=dead |newspaper=The Mariners Weather Log |date=April 1999 |access-date=October 1, 2005}} * {{Cite news |title=Q&A with Herbert Saffir |url=http://www.novalynx.com/saffir-interview.html |archive-url=https://web.archive.org/web/20100228001734/http://www.novalynx.com/saffir-interview.html |archive-date=February 28, 2010 |url-status=dead |newspaper=The South Florida Sun-Sentinel |date=June 2001 |access-date=October 1, 2005}}

{{DEFAULTSORT:Saffir-Simpson scale}} Category:1973 introductions Category:Atlantic hurricanes Category:Hazard scales Category:Pacific hurricanes Category:Scales in meteorology Category:Tropical cyclone meteorology Category:Wind