Pickens County
Population 18,221 (2025) 881 sq mi
Pickens County has recorded 55 tornadoes since 1950, 15th 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 195055
- Tropical cyclone tracks within 100 miles since 1851, wider where stronger27
- Wildfire burn scars since 19841
- Major flood years since 19781
At a glance
The record for Pickens County in eight numbers. Each links to its section below.
Tropical cyclones within 50 mi
16
33rd of 67 in Alabama
None at hurricane strength since 1851
DetailsAcres burned since 1984
757
28th of 67 in Alabama
1 large fire; the largest was Co Rd 2 And Emory Chapel Rd Fire, 2021
DetailsStrongest tornado
F5
March 3, 1966, 202.5 mile path
Strongest tropical cyclone
TS
Tropical storm Zeta, 2020, 31.2 miles away
Tornadoes
About one every 1.4 years since 1950, 11 of them rated F3/EF3 or stronger.
Strongest
March 3, 1966
F5, 202.5 mile path
900 yards wide; 58 killed along the whole path.
Most recent
Saturday, March 15, 2025
EF2, 21.6 mile path
Within the past year.
Every recorded tornado
| Mar 15, 2025 | EF2 | 21.6 | 0 | 0 |
| Mar 15, 2025 | EF1 | 26.5 | 0 | 0 |
| Jan 5, 2025 | EF1 | 6.9 | 0 | 0 |
| Mar 30, 2022 | EF1 | 16.6 | 0 | 0 |
| Mar 25, 2021 | EF1 | 6.6 | 0 | 0 |
| Apr 12, 2020 | EF0 | 5.5 | 0 | 0 |
| Apr 12, 2020 | EF0 | 1.5 | 0 | 0 |
| Jan 11, 2020 | EF2 | 6.3 | 7 | 3 |
| Feb 23, 2019 | EF0 | 1.1 | 0 | 0 |
| Aug 31, 2017 | EF2 | 31.2 | 6 | 0 |
| Nov 29, 2016 | EF1 | 5.3 | 0 | 0 |
| Mar 31, 2016 | EF1 | 2.9 | 0 | 0 |
| Mar 31, 2016 | EF1 | 7.8 | 0 | 0 |
| Feb 23, 2016 | EF0 | 4.8 | 0 | 0 |
| Feb 2, 2016 | EF0 | 4.2 | 0 | 0 |
| Feb 2, 2016 | EF2 | 26.2 | 1 | 0 |
| Apr 28, 2014 | EF2 | 14.3 | 5 | 0 |
| Apr 11, 2013 | EF3 | 66.3 | 9 | 1 |
| Apr 27, 2011 | EF3 | 23.7 | 2 | 0 |
| Apr 27, 2011 | EF4 | 127.8 | 54 | 13 |
| Apr 27, 2011 | EF3 | 22.5 | 0 | 0 |
| Apr 27, 2011 | EF2 | 14.4 | 0 | 0 |
| Apr 27, 2011 | EF2 | 35.2 | 0 | 0 |
| May 6, 2009 | EF1 | 1.3 | 0 | 0 |
| May 6, 2009 | EF1 | 1.0 | 0 | 0 |
| Jan 10, 2008 | EF1 | 2.0 | 0 | 0 |
| Jan 10, 2008 | EF0 | 0.0 | 0 | 0 |
| Sep 25, 2005 | F0 | 0.3 | 0 | 0 |
| Sep 25, 2005 | F0 | 5.2 | 0 | 0 |
| Apr 6, 2005 | F0 | 1.5 | 0 | 0 |
| Mar 13, 2005 | F0 | 7.0 | 0 | 0 |
| Apr 25, 2003 | F1 | 0.1 | 0 | 0 |
| Nov 10, 2002 | F1 | 9.5 | 0 | 0 |
| Nov 10, 2002 | F1 | 51.0 | 0 | 1 |
| Nov 24, 2001 | F3 | 38.9 | 1 | 2 |
| May 9, 1998 | F0 | 6.5 | 0 | 0 |
| May 9, 1998 | F0 | 2.2 | 0 | 0 |
| Apr 8, 1998 | F3 | 19.5 | 1 | 0 |
| Apr 14, 1996 | F1 | 0.5 | 0 | 0 |
| Nov 22, 1992 | F2 | 2.0 | 7 | 0 |
| Apr 12, 1991 | F0 | 0.3 | 0 | 0 |
| Feb 3, 1990 | F0 | 0.5 | 0 | 0 |
| May 16, 1988 | F1 | 0.5 | 0 | 0 |
| Mar 12, 1986 | F3 | 16.0 | 0 | 2 |
| Nov 10, 1984 | F2 | 14.0 | 0 | 0 |
| Dec 11, 1983 | F0 | 3.0 | 0 | 0 |
| Dec 8, 1978 | F1 | 1.0 | 0 | 0 |
| Mar 20, 1976 | F2 | 0.5 | 0 | 0 |
| Apr 3, 1974 | F4 | 110.6 | 178 | 3 |
| Mar 6, 1967 | F1 | 0.1 | 0 | 0 |
| Mar 3, 1966 | F5 | 202.5 | 518 | 58 |
| Feb 11, 1965 | F3 | 1.5 | 18 | 0 |
| Mar 11, 1963 | F2 | 0.1 | 0 | 0 |
| Nov 8, 1957 | F1 | 8.7 | 5 | 0 |
| Mar 3, 1952 | F3 | 3.3 | 6 | 0 |
- Injuries and deaths are for the tornado’s whole path, which may extend beyond the county. Deaths recorded within Pickens County: 5.
- 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
16 passed within 50 miles since 1851; none at hurricane strength.
Strongest within 50 miles
October 29, 2020
Zeta, Tropical storm
31.2 miles at closest approach, winds near 69 mph.
Most recent
October 29, 2020
Zeta, Tropical storm
31.2 miles at closest approach.
Every storm within 100 miles
| Zeta | 2020 | 31.2 | Tropical storm |
| Olga | 2019 | 83.8 | Post-tropical |
| Katrina | 2005 | 28.7 | Tropical storm |
| Ivan | 2004 | 45.4 | Tropical storm |
| Opal | 1995 | 91.9 | Tropical storm |
| Juan | 1985 | 62.1 | Tropical storm |
| Frederic | 1979 | 0.0 | Tropical storm |
| Camille | 1969 | 98.2 | Tropical storm |
| Audrey | 1957 | 89.8 | Tropical storm |
| Baker | 1950 | 0.0 | Tropical storm |
| Unnamed | 1934 | 76.8 | Tropical storm |
| Unnamed | 1932 | 47.0 | Post-tropical |
| Unnamed | 1932 | 67.2 | Tropical storm |
| Unnamed | 1923 | 44.5 | Tropical storm |
| Unnamed | 1916 | 17.7 | Tropical storm |
| Unnamed | 1916 | 4.5 | Tropical storm |
| Unnamed | 1915 | 8.5 | Post-tropical |
| Unnamed | 1912 | 9.3 | Tropical storm |
| Unnamed | 1912 | 48.3 | Tropical storm |
| Unnamed | 1907 | 66.8 | Tropical storm |
| Unnamed | 1906 | 62.9 | Tropical storm |
| Unnamed | 1901 | 17.8 | Tropical storm |
| Unnamed | 1892 | 21.3 | Tropical storm |
| Unnamed | 1881 | 0.0 | Tropical storm |
| Unnamed | 1879 | 12.6 | Tropical storm |
| Unnamed | 1860 | 83.0 | Tropical storm |
| Unnamed | 1860 | 3.4 | Tropical storm |
| Unnamed | 1859 | 99.9 | Tropical storm |
| Unnamed | 1855 | 0.0 | Tropical storm |
| Unnamed | 1852 | 92.9 | 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
757 acres burned in 1 large fire since 1984, equal to 0.1% of the land.
Largest
February 26, 2021
Co Rd 2 And Emory Chapel Rd Fire, 759 acres
757 acres inside Pickens County.
Most recent
February 26, 2021
Co Rd 2 And Emory Chapel Rd Fire
759 acres in total.
Every large fire
| Co Rd 2 And Emory Chapel Rd Fire | 2021 | 757 | 759 |
- 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: 49 days
Heavy smoke on 4 days in 2023, the most of any year.
Last 10 years
12.2 days a year
Medium or heavy smoke, 2016 to 2025.
2025
10 days
Medium or heavy smoke. 40 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
116 federal flood insurance claims since 1978, with $1.2 million paid.
Most claims in one year
1991: 27 claims
$169,000 paid.
2nd most
2019: 14 claims
$276,000 paid.
3rd most
2004: 13 claims
$147,000 paid.
Claims by ZIP code
| 35447 | 83 | $904,000 |
| 35481 | 13 | $190,000 |
| 6 | $41,000 | |
| 35442 | 5 | $46,000 |
Flood events since 1996
- Flash Flood14
- Flood6
2 deaths recorded in flood events since 1996.
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 23, 1991
Tombigbee River at Bevill Lock and Dam, 142.95 ft
20.95 feet above the 122.0 ft flood stage; major flooding by today’s categories.
Most recent moderate or major crest
June 13, 2021
Tombigbee River at Bevill Lock and Dam, 134.60 ft
Moderate flooding.
River gauges
| Tombigbee River at Bevill Lock and Dam | 122.0 | 142.95 ft | 12 |
- 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 119 of 1,581 months since 1895 (8%); the longest spell lasted 18 months.
119
Months in severe drought or worse since 1895
29
Months in extreme drought
8%
Share of all months, severe or worse
36
Drought reports to the Weather Service since 1996
Lowest reading
September 1954
−5.83, extreme drought
Longest severe spell
18 months
April 1897 to September 1898.
Latest month
September 2026
−1.14, mild drought
Last severe month: March 2017.
- 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 4.5 in 1975.
1
Magnitude 2.5+ inside the county since 1973
23
Magnitude 3+ within 50 miles since 1973
2
Magnitude 4+ within 50 miles since 1900
0
Magnitude 5+ within 50 miles since 1900
Largest within 50 miles
June 24, 1975
Magnitude 4.5
3 km NNW of Fayette, Alabama; 13.4 miles away, 6.2 miles deep.
Most recent, magnitude 3 or more
June 30, 2015
Magnitude 3.5
12 km W of Union, Alabama; 2.9 miles away.
Every earthquake of magnitude 4 or more within 50 miles
| Nov 7, 2004 | 4.3 | 27.3 |
| Jun 24, 1975 | 4.5 | 13.4 |
- 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
403 events in the National Weather Service record, 330 of them since 1996.
49
Hail reports, 1 inch or larger
6
Hail, 2 inches or larger
108
Damaging gusts, 58 mph+
18
Winter weather events since 1996
9
Heat events since 1996
6
Cold events since 1996
Largest hail
June 16, 2023
2.75 inches
Strongest measured or estimated gust
July 6, 2012
90 mph
More event types since 1996
| Lightning | 1 | 0 |
Costliest events since 1996
- Apr 27, 2011Tornado$3.8 million
National Weather Service narrative
The first segment of this long track tornado initially touched down 5 miles northeast of Pickensville near Basinger Rd, north of AL Hwy 86. This tornado continued through portions of Tuscaloosa, Fayette, Walker, Cullman (See Storm Data for Huntsville), and Blount Counties, before it dissipated in Marshall (See Storm Data for Huntsville) County. While the average path width of this tornado in Pickens County was around 0.4 mile (704 yds), the maximum path width was 0.6 mile (1056 yds). The tornado crossed AL Hwy 17 and US Hwy 82, across the southern and western extents of the city of Reform. The storm strengthened to an EF1 rating with winds of 110 mph to the northeast of Reform.…
- Apr 27, 2011Tornado$2.9 million
National Weather Service narrative
A tornado developed along a Quasi-Linear Convective System and touched down in Kemper County Mississippi (See Storm Data Jackson), then tracked northeast through Noxubee County before crossing into Pickens County, southwest of Dancy. The tornado weakened to an EF1 rating as it entered Alabama, with winds of 100 mph. As the tornado moved across AL Hwy 17 near Dancy, a barn with metal siding and roofing and two small silos were destroyed. Significant tree damage was noted along CR 85. The tornado crossed the Tombigbee River and moved parallel to CR 13. The tornado crossed AL Hwy 14 south of Aliceville, damaging a farm irrigation system. The tornado continued northeast, lifting near…
- Apr 27, 2011Tornado$1.8 million
National Weather Service narrative
A tornado developed along a Quasi-Linear Convective System. It touched down in central Pickens County, northwest of Carrollton, near the intersection of CR 7 and CR 26, where trees were snapped off. The tornado moved northeast and strengthened to an EF2 rating with winds of 120 mph as it approached CR 35 where it downed thousands of trees. The tornado crossed US Hwy 82 and AL Hwy 17 where it caused mostly tree damage across northwestern portions of Reform. East of AL Hwy 17, at least two outbuildings sustained roof damage along CR 3. Near the end of the tornado path, a home sustained minor wall damage and significant roof damage. The tornado lifted along CR 3, south of CR 57.
- Apr 27, 2011Tornado$1.6 million
National Weather Service narrative
A tornado initially touched down in Kemper County Mississippi (See Storm Data Jackson), near Scooba, and tracked northeast through Sumter County, Alabama and into southern Pickens County just west of CR 85. As the tornado strengthened to an EF3 rating with winds of 140, the path width decreased to 0.4 mile (704 yds). As the tornado crossed CR 85, a large cinder block building sustained significant loss of roofing and partial wall collapse. The tornado continued to cause tree damage along its path as it moved northeast and crossed the Tombigbee River at Vienna. The tornado weakened and lifted at AL Hwy 14, just north of the Sipsey River.
- Sep 16, 2004High Wind, Pickens$600,000
National Weather Service narrative
Hundreds of trees and power lines were knocked down in association with Ivan. Power outages lasted as long as 5 days in some locations. Hundreds of homes suffered varying degrees of wind damage. Maximum wind gusts were estimated around 65 miles an hour.
- Aug 29, 2005Tropical Storm, Pickens$500,000
National Weather Service narrative
Extensive tree and power line damage occurred as Katrina affected the area. Many roadways were impassable due to fallen trees. Power outages were widespread. Several structures were damaged. One grocery store had its roof torn off. One person was slightly injured when a tree fell on their home.
- Apr 8, 2002Thunderstorm Wind$300,000
National Weather Service narrative
A line of thunderstorms moved through Pickens County and produced wind damage generally across the eastern and southern parts of the county. Trees and power lines were blown down around Aliceville and Reform. Structural damage was reported to the Winn Dixie in Aliceville. Three chicken houses were destroyed just northeast of Gordo and hundreds of chickens were killed. Two airport hangars were destroyed north of Gordo. No injuries were reported.
- Apr 14, 1996Tornado$200,000
National Weather Service narrative
In Aliceville, two mobile homes were destroyed and 12 houses and two other buildings were damaged by falling trees. A nursing home roof was taken off and several cars were damaged by falling trees in what was apparently a tornado.
- Mar 13, 2005Tornado$175,000
National Weather Service narrative
National Weather Service Meteorologist surveyed the damage in Pickens County and determined a weak tornado occurred. The tornado damage was rated an F0. The tornado first touched down just west ofCR 75 near the Pine Grove Community. The tornado tracked east northeast through the Pine Grove Community, where one home suffered extensive damage from fallen and uprooted trees. The tornado continued almost parallel to Will Jones Road where two homes sustained significant damage. The tornado ended near the intersection of Will Jones Road and Moorehead Road just south of the McShanCommunity. Numerous trees were blown down or uprooted along the path and a few outbuildings weredestroyed.…
- Feb 16, 2001Thunderstorm Wind$100,000
National Weather Service narrative
Pickens County reported numerous trees and power lines knocked down. Numerous homes reported roof damage.
- 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 Tuscaloosa Airport Asos, 27 miles from the county’s population centre, with records from 1948.
- All-time high
- 107°F5 times, most recently Aug 10, 2007
- All-time low
- −1°F2 times, most recently Jan 21, 1985
- Warmest night
- 81°FJul 10, 2000
- Coldest day
- 18°F2 times, most recently Dec 22, 1989
- Wettest day
- 8.16 inJun 19, 2021
- Snowiest day
- 7.0 inFeb 13, 1960
- Hottest year
- 2019mean 66.9°F
- Coldest year
- 1976mean 61.0°F
- Wettest year
- 198378.35 in
- Driest year
- 200725.56 in
- Snowiest season
- 7.0 in1959-60
Median first snow
January 31
Earliest: December 31, 1963
Median last snow
January 31
Latest: March 13, 1993
33 of 47 winters had no measurable snow.
Station Tuscaloosa Airport Asos (USW00093806), 148 ft elevation, 27.0 miles from the population centre. Daily records from 1948 to October 26, 2026; 91.4% 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
19 since 1953. The most recent: Hurricane Helene, September 26, 2024.
| Sep 26, 2024 | Hurricane | EM-3618-AL |
| Sep 14, 2020 | Hurricane | EM-3545-AL |
| Mar 29, 2020 | Biological | DR-4503-AL |
| Mar 13, 2020 | Biological | EM-3472-AL |
| Sep 11, 2017 | Hurricane | EM-3389-AL |
| May 2, 2014 | Severe Storm | DR-4176-AL |
| Sep 21, 2012 | Hurricane | DR-4082-AL |
| Apr 28, 2011 | Severe Storm | DR-1971-AL |
| Apr 27, 2011 | Severe Storm | EM-3319-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 |
| Nov 14, 2002 | Severe Storm | DR-1442-AL |
| Mar 15, 1993 | Snowstorm | EM-3096-AL |
| Apr 18, 1979 | Flood | DR-578-AL |
| Jul 20, 1977 | Drought | EM-3045-AL |
| Apr 4, 1974 | Tornado | DR-422-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 Pickens County stands among 67 counties in Alabama and 3,143 in the United States.
| Tornadoes since 1950 | 55 | 15 / 67 |
| Tornadoes rated F3/EF3 or stronger | 11 | 6 / 67 |
| Tropical cyclones within 50 mi | 16 | 33 / 67 |
| Hurricane-strength passes within 50 mi | 0 | — |
| Wildfire acres since 1984 | 757 | 28 / 67 |
| Flood insurance claims | 116 | 19 / 67 |
| Flood insurance paid | $1.2 million | 20 / 67 |
| Disaster declarations | 19 | 67 / 67 |
| Flood events since 1996 | 20 | 48 / 67 |
| Hail and wind events since 1996 | 197 | 45 / 67 |
| Winter storm events since 1996 | 18 | 30 / 67 |
| Reported damage since 1996 | $13.3 million | 45 / 67 |
| River crests at major flood stage | 12 | 5 / 67 |
| High tide flooding days a year, last 10 years | 0.0 | — |
| Months in severe drought since 1895 | 119 | 17 / 67 |
| Medium or heavy smoke days a year, last 10 years | 12.2 | 2 / 67 |
| Earthquakes M4+ within 50 mi since 1900 | 2 | 22 / 67 |
| Earthquakes M2.5+ in the county since 1973 | 1 | 28 / 67 |
Neighbouring counties
| Fayette County | 55 | 13 |
| Greene County | 29 | 18 |
| Lamar County | 42 | 11 |
| Lowndes County MS | 51 | 14 |
| Noxubee County MS | 52 | 17 |
| Sumter County | 31 | 24 |
| Tuscaloosa County | 94 | 16 |
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 USW00093806.
- 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.