Perry County
Population 7,425 (2025) 720 sq mi
Perry County has recorded 40 tornadoes since 1950, 40th most of 67 counties in Alabama; the most recent was on March 15, 2025.
Hazard fingerprint Each spoke is this county’s percentile among U.S. counties where that hazard occurs. How it is computed
- Tornado damage paths since 195040
- Tropical cyclone tracks within 100 miles since 1851, wider where stronger37
- Wildfire burn scars since 19843
At a glance
The record for Perry County in eight numbers. Each links to its section below.
Tropical cyclones within 50 mi
20
26th of 67 in Alabama
None at hurricane strength since 1851
DetailsAcres burned since 1984
4,522
14th of 67 in Alabama
3 large fires; the largest was Ok 146, 2022
DetailsStrongest tornado
F4
May 27, 1973, 139.1 mile path
Strongest tropical cyclone
TS
Tropical storm Zeta, 2020, 2.7 miles away
Tornadoes
About one every 1.9 years since 1950, 5 of them rated F3/EF3 or stronger.
Strongest
May 27, 1973
F4, 139.1 mile path
800 yards wide; 7 killed along the whole path.
Most recent
Saturday, March 15, 2025
EF0, 21.6 mile path
Within the past year.
Every recorded tornado
| Mar 15, 2025 | EF0 | 21.6 | 0 | 0 |
| Feb 16, 2025 | EF1 | 18.4 | 2 | 0 |
| Jan 12, 2023 | EF1 | 17.3 | 0 | 0 |
| Jan 12, 2023 | EF2 | 21.9 | 0 | 0 |
| Jan 3, 2023 | EF1 | 0.1 | 0 | 0 |
| Mar 30, 2022 | EF3 | 29.2 | 2 | 0 |
| Mar 30, 2022 | EF2 | 6.0 | 0 | 0 |
| May 4, 2021 | EF0 | 24.8 | 0 | 0 |
| Mar 25, 2021 | EF3 | 79.7 | 13 | 0 |
| Apr 12, 2020 | EF1 | 2.4 | 0 | 0 |
| Dec 16, 2019 | EF0 | 5.3 | 0 | 0 |
| Apr 14, 2019 | EF0 | 6.7 | 0 | 0 |
| Mar 14, 2019 | EF0 | 2.9 | 0 | 0 |
| Mar 14, 2019 | EF1 | 9.4 | 0 | 0 |
| Mar 14, 2019 | EF0 | 4.5 | 0 | 0 |
| Dec 1, 2018 | EF0 | 0.3 | 0 | 0 |
| Nov 17, 2014 | EF1 | 3.5 | 0 | 0 |
| Mar 2, 2012 | EF1 | 18.9 | 0 | 0 |
| Jan 26, 2012 | EF0 | 0.6 | 0 | 0 |
| Jan 23, 2012 | EF2 | 39.8 | 0 | 0 |
| Jan 23, 2012 | EF1 | 2.1 | 0 | 0 |
| Apr 27, 2011 | EF1 | 4.2 | 0 | 0 |
| Apr 27, 2011 | EF4 | 122.0 | 17 | 7 |
| Apr 15, 2011 | EF2 | 0.8 | 0 | 0 |
| Apr 15, 2011 | EF0 | 4.7 | 0 | 0 |
| Nov 30, 2010 | EF1 | 0.1 | 0 | 0 |
| Apr 19, 2009 | EF1 | 1.2 | 0 | 0 |
| Apr 19, 2009 | EF1 | 4.0 | 0 | 0 |
| Feb 13, 2007 | EF0 | 6.5 | 0 | 0 |
| Oct 13, 2001 | F1 | 1.5 | 0 | 0 |
| Dec 16, 2000 | F0 | 0.7 | 0 | 0 |
| Mar 10, 2000 | F0 | 12.0 | 0 | 0 |
| Mar 10, 2000 | F0 | 7.0 | 0 | 0 |
| Mar 6, 1996 | F1 | 1.5 | 0 | 0 |
| Sep 20, 1979 | F2 | 3.0 | 2 | 0 |
| Apr 22, 1974 | F2 | 2.0 | 0 | 0 |
| May 27, 1973 | F4 | 139.1 | 199 | 7 |
| Mar 6, 1967 | F2 | 2.3 | 0 | 0 |
| Dec 17, 1961 | F2 | 5.4 | 1 | 0 |
| Dec 11, 1961 | F3 | 9.4 | 2 | 0 |
- Injuries and deaths are for the tornado’s whole path, which may extend beyond the county. Deaths recorded within Perry County: 0.
- Weak tornadoes were under-recorded before Doppler radar coverage became national in the early 1990s, so earlier decades read low. Ratings use the Fujita scale before February 2007 and the Enhanced Fujita scale after.
Storm Prediction Center severe weather database, 1950 to 2025.
Hurricanes and tropical storms
20 passed within 50 miles since 1851; none at hurricane strength.
Strongest within 50 miles
October 29, 2020
Zeta, Tropical storm
2.7 miles at closest approach, winds near 69 mph.
Most recent
October 29, 2020
Zeta, Tropical storm
2.7 miles at closest approach.
Every storm within 100 miles
| Zeta | 2020 | 2.7 | Tropical storm |
| Katrina | 2005 | 86.7 | Tropical storm |
| Dennis | 2005 | 38.1 | Tropical storm |
| Ivan | 2004 | 0.0 | Tropical storm |
| Opal | 1995 | 38.4 | Tropical storm |
| Erin | 1995 | 80.7 | Tropical storm |
| Juan | 1985 | 11.2 | Tropical storm |
| Frederic | 1979 | 54.2 | Tropical storm |
| Eloise | 1975 | 71.7 | Category 1 |
| Baker | 1950 | 31.0 | Tropical storm |
| Unnamed | 1932 | 0.0 | Post-tropical |
| Unnamed | 1932 | 90.6 | Tropical storm |
| Unnamed | 1923 | 91.0 | Tropical storm |
| Unnamed | 1916 | 0.0 | Tropical storm |
| Unnamed | 1916 | 26.0 | Tropical storm |
| Unnamed | 1915 | 73.1 | Post-tropical |
| Unnamed | 1912 | 56.9 | Tropical storm |
| Unnamed | 1912 | 0.0 | Tropical storm |
| Unnamed | 1907 | 5.6 | Tropical storm |
| Unnamed | 1906 | 99.2 | Tropical storm |
| Unnamed | 1906 | 74.8 | Tropical storm |
| Unnamed | 1903 | 67.9 | Tropical storm |
| Unnamed | 1902 | 61.4 | Tropical storm |
| Unnamed | 1901 | 35.0 | Tropical storm |
| Unnamed | 1893 | 41.5 | Tropical storm |
| Unnamed | 1893 | 82.7 | Tropical storm |
| Unnamed | 1892 | 10.6 | Tropical storm |
| Unnamed | 1889 | 98.1 | Tropical storm |
| Unnamed | 1887 | 79.6 | Tropical storm |
| Unnamed | 1887 | 93.6 | Tropical storm |
| Unnamed | 1881 | 4.1 | Tropical storm |
| Unnamed | 1880 | 47.2 | Tropical storm |
| Unnamed | 1879 | 11.0 | Tropical storm |
| Unnamed | 1879 | 75.3 | Tropical storm |
| Unnamed | 1860 | 32.8 | Tropical storm |
| Unnamed | 1860 | 77.2 | Tropical storm |
| Unnamed | 1859 | 38.4 | Tropical storm |
| Unnamed | 1855 | 49.4 | Tropical storm |
| Unnamed | 1852 | 31.7 | Tropical storm |
- Tropical storms and hurricanes (34 kt or more, still tropical) at closest approach. Post-tropical remnants with gale-force winds are listed but not counted. Direct: track within 50 miles; near: within 100 miles. Distance is measured to the county boundary for counties and to the city centre for cities, using positions interpolated hourly between HURDAT2 fixes.
National Hurricane Center HURDAT2, 1851 to 2025.
Wildfire and smoke
4,522 acres burned in 3 large fires since 1984, equal to 1.0% of the land.
Largest
February 15, 2022
Ok 146 Fire, 2,639 acres
2,640 acres inside Perry County.
Most recent
October 10, 2022
Ok 143 Fire
531 acres in total.
Every large fire
| Ok 143 | 2022 | 532 | 531 |
| Ok 146 | 2022 | 2,640 | 2,639 |
| Unnamed | 1987 | 1,349 | 1,349 |
- Large fires mapped by the Monitoring Trends in Burn Severity program since 1984: 1,000 acres or more in the West, 500 or more in the East. Prescribed burns are excluded. Acres here are the part of each perimeter inside this place.
Monitoring Trends in Burn Severity (USGS and U.S. Forest Service), 1984 to 2026.
Smoke overhead
Smokiest year
2023: 48 days
Heavy smoke on 4 days in 2023, the most of any year.
Last 10 years
11.5 days a year
Medium or heavy smoke, 2016 to 2025.
2025
8 days
Medium or heavy smoke. 38 so far in 2026.
- A smoke day is a date on which a smoke plume traced by NOAA Hazard Mapping System analysts from satellite imagery covered this place's point (the county's population centre or the city centre). Counts here are of medium or heavy smoke. Since 2018 analysts have often drawn light smoke as one area over most of the continent, so light-smoke counts are not comparable from year to year. The plumes show smoke anywhere in the air above, not air quality at the ground, and smoke hidden by cloud is missed.
NOAA Hazard Mapping System smoke analysis, 2011 to 2026, retrieved October 30, 2026.
Floods and flood insurance
2 federal flood insurance claims since 1990, with $7,315 paid.
Flood events since 1996
- Flash Flood9
- Flood1
- Heavy Rain1
This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).
OpenFEMA NFIP Redacted Claims v3, refreshed August 4, 2026. NOAA Storm Events through 2026.
River crests
Most severe crest
February 25, 1961
Cahaba River at Suttle, 44.00 ft
12.00 feet above the 32.0 ft flood stage; moderate flooding by today’s categories.
Most recent moderate or major crest
February 25, 1961
Cahaba River at Suttle, 44.00 ft
Moderate flooding.
| Feb 25, 1961 | Cahaba River at Suttle | 44.00 | +12.00 |
| Mar 30, 1951 | Cahaba River at Suttle | 42.80 | +10.80 |
| Apr 15, 1979 | Cahaba River at Suttle | 41.55 | +9.55 |
| Feb 18, 1990 | Cahaba River at Suttle | 41.09 | +9.09 |
| Mar 18, 1976 | Cahaba River at Suttle | 40.23 | +8.23 |
| Mar 23, 1970 | Cahaba River at Suttle | 40.00 | +8.00 |
| Apr 1, 1977 | Cahaba River at Suttle | 39.14 | +7.14 |
| Jan 13, 1972 | Cahaba River at Suttle | 38.20 | +6.20 |
| Apr 10, 2014 | Cahaba River at Suttle | 37.18 | +5.18 |
| Mar 14, 2010 | Cahaba River at Suttle | 36.79 | +4.79 |
| Dec 31, 2018 | Cahaba River at Suttle | 36.75 | +4.75 |
| Jan 10, 1998 | Cahaba River at Suttle | 36.58 | +4.58 |
| Apr 6, 2000 | Cahaba River at Suttle | 36.50 | +4.50 |
| Jun 26, 2017 | Cahaba River at Suttle | 36.43 | +4.43 |
| Mar 19, 1990 | Cahaba River at Suttle | 36.19 | +4.19 |
| Mar 15, 1980 | Cahaba River at Suttle | 36.04 | +4.04 |
| Sep 24, 2009 | Cahaba River at Suttle | 35.82 | +3.82 |
| Mar 10, 1996 | Cahaba River at Suttle | 35.58 | +3.58 |
| Mar 12, 2011 | Cahaba River at Suttle | 34.98 | +2.98 |
| Feb 25, 1971 | Cahaba River at Suttle | 34.00 | +2.00 |
| Jan 30, 1996 | Cahaba River at Suttle | 33.50 | +1.50 |
| Feb 2, 1999 | Cahaba River at Suttle | 33.29 | +1.29 |
| Apr 4, 2005 | Cahaba River at Suttle | 33.19 | +1.19 |
| Feb 5, 1996 | Cahaba River at Suttle | 33.10 | +1.10 |
| Jan 23, 1990 | Cahaba River at Suttle | 32.26 | +0.26 |
River gauges
| Cahaba River at Suttle | 32.0 | 44.00 ft | 0 |
- Crests are the highest and the recent crests the National Weather Service lists for each river gauge in the county that has a flood stage, not every flood. Flood categories use each gauge's current flood stages; crests from before levees, dams or channel changes may not be comparable. Crests measured on an old datum are left out of the rankings.
NOAA National Water Prediction Service gauge records, retrieved October 30, 2026.
Drought
In severe drought or worse for 115 of 1,581 months since 1895 (7%); the longest spell lasted 17 months.
115
Months in severe drought or worse since 1895
28
Months in extreme drought
7%
Share of all months, severe or worse
41
Drought reports to the Weather Service since 1996
Lowest reading
October 1954
−5.19, extreme drought
Longest severe spell
17 months
June 1897 to October 1898.
Latest month
September 2026
−3.63, severe drought
- The Palmer Drought Severity Index is computed by NOAA each month from the county's average temperature and precipitation, relative to the county's own climate. Zero is normal; -3 or lower is severe drought and -4 or lower extreme drought. It describes the long-term balance of moisture, not water supply or crop losses.
NOAA NCEI nClimDiv county Palmer Drought Severity Index, 1895 to September 2026, issued October 6, 2026.
Earthquakes
2 earthquakes of magnitude 4 or more within 50 miles since 1900; the largest was magnitude 5.1 in 1916.
4
Magnitude 2.5+ inside the county since 1973
19
Magnitude 3+ within 50 miles since 1973
2
Magnitude 4+ within 50 miles since 1900
1
Magnitude 5+ within 50 miles since 1900
Largest within 50 miles
October 18, 1916
Near Irondale, Alabama; 49.4 miles away, 8.7 miles deep.
Most recent, magnitude 3 or more
December 22, 2021
Magnitude 3.1
10 km E of Maplesville, Alabama; 15.1 miles away.
Every earthquake of magnitude 4 or more within 50 miles
| Nov 7, 2004 | 4.3 | 23.7 |
| Oct 18, 1916 | 5.1 | 49.4 |
- Earthquakes of magnitude 2.5 or more in the USGS Comprehensive Catalog since 1900. Within 50 miles means the epicentre lies within 50 miles of the county boundary (or inside the county).
- Small earthquakes were under-recorded before the modern seismic networks of the 1970s and are still missed in remote areas, so early decades read low. Magnitudes are as the catalogue reports them and mix scales (moment, local and body-wave).
USGS ANSS Comprehensive Earthquake Catalog, 1900 to present, retrieved October 30, 2026.
Severe weather and other events
240 events in the National Weather Service record, 218 of them since 1996.
32
Hail reports, 1 inch or larger
4
Hail, 2 inches or larger
51
Damaging gusts, 58 mph+
8
Winter weather events since 1996
10
Heat events since 1996
6
Cold events since 1996
Largest hail
April 25, 2003
2.50 inches
Strongest measured or estimated gust
March 9, 2011
86 mph
Costliest events since 1996
- Sep 16, 2004High Wind, Perry$3.5 million
National Weather Service narrative
Thousands of trees and power lines were snapped off or blown down. At least 1100 customers were without power. Power was not completely restored in some spots for two weeks. Several hundred homes and mobile homes were damaged. Many county roads were blocked and impassable due to fallen trees. Maximum wind gusts were estimated around 90 miles an hour.
- Apr 27, 2011Tornado$1.3 million
National Weather Service narrative
A tornado touched down 5.5 miles south of Marion, 1 mile west of CR 35 and tracked northeastward. The tornado destroyed an outbuilding and damaged the roof of a single family home along CR 38. The tornado strengthened to EF1 with winds of 90 mph as it crossed CR 45, north of Vilula. Many trees were knocked down near the Faith Chapel Baptist Church. The tornado damaged a couple barns along Kynard Rd and quickly dissipated just east of CR 4.
- Aug 29, 2005Tropical Storm, Perry$1.0 million
National Weather Service narrative
Numerous trees and power lines were blown down during Katrina. Power outages were widespread and in some cases lasted for a week. At least 2200 customers were without power. Several roadways were blocked by fallen trees and were impassable.
- Apr 27, 2011Tornado$645,000
National Weather Service narrative
A tornado touched down in Smith County, Mississippi and tracked through Jasper and Clarke Counties (See Storm Data Jackson), where it caused EF4 rated damage. The tornado then crossed into Choctaw County (See Storm Data Mobile) Alabama, where it caused EF3 rated damage. The tornado tracked across portions of Sumter, Marengo and western Perry Counties, before it dissipated. The tornado crossed into Perry County north of Uniontown and produced significant tree damage. The tornado crossed AL Hwy 183, where it damaged two outbuildings and destroyed a grain silo. The tornado lifted east of AL Hwy 183, northeast of Uniontown.
- May 2, 2003Hail$250,000
National Weather Service narrative
Golf ball size hail pelted areas in and around Uniontown. Several automobiles were damaged. Numerous trees were also blown down in extreme southern Perry County.
- Jul 10, 2005Tropical Storm, Perry$240,000
National Weather Service narrative
Numerous trees and power lines were downed as Dennis moved across the area. At least 2200 customers were without power for many hours. Several vehicles and homes were damaged by fallen trees.
- Apr 10, 2004Thunderstorm Wind$150,000
National Weather Service narrative
A supercell thunderstorm moved across Greene, Hale, and Perry Counties and produced significant wind damage along with very large hail. The supercell produced minor tree damage in extreme northwest Greene County north of Boligee and then became stronger. The most extensive damage started just northeast of Eutaw, in Greene County, along US 11 and ended just north of the Wedgewood community, in Hale County, along SR 60. The swath of damage was 1.5 miles wide at the beginning point and 3 miles wide at the ending point. The path length was approximately 6.5 miles long. Inside this extensive damage area, thousands of trees were snapped off or uprooted, numerous power lines were snapped…
- Oct 13, 2001Tornado$110,000
National Weather Service narrative
A small tornado touched down just southwest of Uniontown in an open area and traveled north-northeast across the western portions of Uniontown. The tornado ended just north-northwest of Uniontown in an open area. The tornado tore shingles off several houses in the southwest section of Uniontown in addition to downing trees and power lines. The tornado did similar damage to residential structures in the northwest portion of Uniontown. A one-story apartment complex lost a portion of it's roof. Several trees fell on homes and blocked residential streets. Beginning: 32 26.587/87 31.219 End: 32 27.857/87 30.951
- May 3, 2009Thunderstorm Wind$100,000
National Weather Service narrative
Thousands of trees were blown down across Perry County.
- Mar 6, 1996Tornado$95,000
National Weather Service narrative
A tornado struck a farm on Highway 183 west-southwest of Marion destroying several farm buildings and downing a number of trees.
- Storm Events records before 1996 cover only tornadoes, thunderstorm wind and hail. Damage figures are as reported by the National Weather Service at the time, not adjusted for inflation.
NOAA NCEI Storm Events Database, 1950 to 2026, issued October 26, 2026.
Weather records
From Marion Junction 2 Ne, 11.3 miles from the county’s population centre, with records from 1950.
- All-time high
- 108°FJul 25, 1952
- All-time low
- −1°F2 times, most recently Jan 22, 1985
- Warmest night
- 79°F5 times, most recently Jul 28, 2026
- Coldest day
- 17°FDec 23, 1989
- Wettest day
- 7.63 inApr 6, 1964
- Snowiest day
- 4.0 inJan 1, 1964
- Hottest year
- 2016mean 66.5°F
- Coldest year
- 1983mean 59.9°F
- Wettest year
- 196176.31 in
- Driest year
- 195427.43 in
Station Marion Junction 2 Ne (USC00015121), 224 ft elevation, 11.3 miles from the population centre. Daily records from 1950 to October 26, 2026; 97.5% of days in the last 30 years are complete. Records at a single station can differ from a city’s official threaded record, which may combine several stations.
NOAA NCEI Global Historical Climatology Network Daily.
Federal disaster declarations
24 since 1953. The most recent: Hurricane Helene, September 26, 2024.
| Sep 26, 2024 | Hurricane | EM-3618-AL |
| Apr 26, 2021 | Severe Storm | DR-4596-AL |
| Dec 10, 2020 | Hurricane | DR-4573-AL |
| Sep 14, 2020 | Hurricane | EM-3545-AL |
| May 21, 2020 | Severe Storm | DR-4546-AL |
| Mar 29, 2020 | Biological | DR-4503-AL |
| Mar 13, 2020 | Biological | EM-3472-AL |
| Oct 8, 2017 | Hurricane | EM-3394-AL |
| Sep 11, 2017 | Hurricane | EM-3389-AL |
| Jan 21, 2016 | Severe Storm | DR-4251-AL |
| May 2, 2014 | Severe Storm | DR-4176-AL |
| Sep 21, 2012 | Hurricane | DR-4082-AL |
| Feb 1, 2012 | Severe Storm | DR-4052-AL |
| Apr 28, 2011 | Severe Storm | DR-1971-AL |
| Apr 27, 2011 | Severe Storm | EM-3319-AL |
| Apr 28, 2009 | Severe Storm | DR-1835-AL |
| Aug 30, 2008 | Hurricane | EM-3292-AL |
| Sep 10, 2005 | Hurricane | EM-3237-AL |
| Aug 29, 2005 | Hurricane | DR-1605-AL |
| Jul 10, 2005 | Hurricane | DR-1593-AL |
| Sep 15, 2004 | Hurricane | DR-1549-AL |
| Mar 15, 1993 | Snowstorm | EM-3096-AL |
| Jul 20, 1977 | Drought | EM-3045-AL |
| May 29, 1973 | Flood | DR-388-AL |
This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).
OpenFEMA Disaster Declarations Summaries, retrieved October 30, 2026. Statewide declarations are not listed.
How this compares
Where Perry County stands among 67 counties in Alabama and 3,143 in the United States.
| Tornadoes since 1950 | 40 | 40 / 67 |
| Tornadoes rated F3/EF3 or stronger | 5 | 23 / 67 |
| Tropical cyclones within 50 mi | 20 | 26 / 67 |
| Hurricane-strength passes within 50 mi | 0 | — |
| Wildfire acres since 1984 | 4,522 | 14 / 67 |
| Flood insurance claims | 2 | 61 / 67 |
| Flood insurance paid | $7,315 | 62 / 67 |
| Disaster declarations | 24 | 37 / 67 |
| Flood events since 1996 | 11 | 64 / 67 |
| Hail and wind events since 1996 | 102 | 65 / 67 |
| Winter storm events since 1996 | 8 | 55 / 67 |
| Reported damage since 1996 | $8.0 million | 48 / 67 |
| River crests at major flood stage | 0 | — |
| High tide flooding days a year, last 10 years | 0.0 | — |
| Months in severe drought since 1895 | 115 | 21 / 67 |
| Medium or heavy smoke days a year, last 10 years | 11.5 | 10 / 67 |
| Earthquakes M4+ within 50 mi since 1900 | 2 | 22 / 67 |
| Earthquakes M2.5+ in the county since 1973 | 4 | 13 / 67 |
Neighbouring counties
| Bibb County | 39 | 13 |
| Chilton County | 44 | 16 |
| Dallas County | 46 | 22 |
| Hale County | 54 | 18 |
| Marengo County | 47 | 22 |
Sources and vintage
Every number on this page comes from these public records.
- Tornadoes NOAA Storm Prediction Center severe weather database, through 2025.
- Tropical cyclones NOAA National Hurricane Center HURDAT2 (Atlantic; Northeast and Central Pacific), through 2025.
- Wildfire USGS/USFS Monitoring Trends in Burn Severity, through 2026.
- Storm events NOAA NCEI Storm Events Database, through 2026.
- Flood insurance OpenFEMA NFIP Redacted Claims v3, refreshed August 4, 2026.
- Declarations OpenFEMA Disaster Declarations Summaries v2, retrieved October 30, 2026.
- Weather records NOAA NCEI Global Historical Climatology Network Daily, station USC00015121.
- River crests NOAA National Weather Service, National Water Prediction Service river gauges, retrieved October 30, 2026.
- Drought NOAA NCEI nClimDiv county Palmer Drought Severity Index, through September 2026.
- Smoke NOAA NESDIS Hazard Mapping System smoke analysis, retrieved October 30, 2026.
- Earthquakes USGS ANSS Comprehensive Earthquake Catalog (ComCat), retrieved October 30, 2026.
Joins, thresholds and known limits are set out in the methodology. Found an error? Report it. Page built October 30, 2026.