Carroll

Population 10,085 (2025)

106 tornadoes have tracked within 25 miles of Carroll since 1950, 5 of them rated EF3 or F3 or stronger; the most recent was on April 26, 2024.

Hazard fingerprint for Carroll Tornado: 80th percentile. Tropical: 0th percentile. Wildfire: 0th percentile. Flood: 78th percentile. Hail & wind: 72th percentile. Heat: 25th percentile. Cold: 77th percentile. Winter: 59th percentile. TORTROPFIREFLOODSEVEREHEATCOLDWINTER

Hazard fingerprint Each spoke is this county’s percentile among U.S. counties where that hazard occurs. How it is computed

2026
  • Tornado damage paths within 25 miles since 1950106

At a glance

Tornado paths within 25 miles, tropical cyclone tracks within 100 miles and wildfire perimeters within 25 miles of the city centre. Storm events, flood insurance claims and disaster declarations are for Carroll County. Earthquakes within 50 miles, volcanoes within 100 miles and smoke days are measured from the city centre; river and tide gauges, tsunami and landslide records and the drought index are for Carroll County.

Tornadoes since 1950, within 25 mi

106

5 rated F3/EF3 or stronger

Details

Flood insurance claims

13

Carroll County

$360,000 paid since 1993

Details

Strongest tornado

F4

May 27, 1995, 36.0 mile path

Federal disaster declarations

16

Most recent: Covid-19 Pandemic, 2020

Details

Record high

112°F

Reached 2 times, most recently July 4, 1936

Details

Record low

−40°F

January 12, 1912

Details

Snowiest season

57.0in

Winter of 1959-60

Costliest event since 1996

$12.7M

Drought, August 1, 2003

Details

Tornadoes

About one tornado a year since 1950, 5 of them rated F3/EF3 or stronger.

Strongest

May 27, 1995

F4, 36.0 mile path

400 yards wide.

Deadliest

June 9, 1954

1 killed, F4

0 injured along the whole path.

Most recent

Friday, April 26, 2024

EF1, 13.0 mile path

2 years ago.

Tornadoes by decade, within 25 miles Doppler radar era² 1950s: 6 6 1960s: 10 10 1970s: 11 11 1980s: 6 6 1990s: 23 23 2000s: 15 15 2010s: 17 17 2020s: 18 18 1950s1960s1970s1980s1990s2000s2010s2020s
Recorded tornadoes per decade. The 2020s are incomplete.
Tornadoes by month J: 0 F: 0 M: 0 A: 13 M: 29 29 J: 13 J: 15 A: 20 S: 4 O: 2 N: 2 D: 8 JFMAMJJASOND
By month of occurrence, all years.

Every recorded tornado

Tornadoes within 25 miles since 1950
Apr 26, 2024EF113.030000
Apr 26, 2024EF29.320000
Apr 16, 2024EF15.27500
Aug 5, 2023EFU0.35000
Aug 5, 2023EF00.93500
Aug 5, 2023EFU0.32500
May 13, 2023EFU0.44000
Jul 7, 2022EFU0.42000
Dec 15, 2021EF119.010000
Dec 15, 2021EFU1.34000
Dec 15, 2021EF22.77000
Dec 15, 2021EF25.810000
Dec 15, 2021EF25.510000
Dec 15, 2021EF19.78000
Dec 15, 2021EF219.710000
Dec 15, 2021EF217.610000
Jul 14, 2021EFU0.83000
Jul 14, 2021EF310.850500
Jun 20, 2018EF00.64000
May 9, 2016EF01.52000
Nov 11, 2015EF01.54000
Oct 23, 2015EF03.54500
May 10, 2015EF123.370000
Aug 31, 2014EF01.410000
Aug 31, 2014EF04.54500
Aug 31, 2014EF05.610000
Aug 31, 2014EF00.86000
Aug 31, 2014EF01.620000
Aug 31, 2014EF00.78000
Aug 31, 2014EF02.614000
Aug 31, 2014EF00.97000
Aug 31, 2014EF05.09000
Aug 31, 2014EF00.716000
Aug 31, 2014EF02.07000
Jun 26, 2011EF12.410000
Jul 19, 2008EF17.810000
May 29, 2008EF14.110000
May 29, 2008EF12.57500
Aug 28, 2007EF00.75000
Aug 28, 2007EF016.25000
Aug 28, 2007EF00.13000
May 6, 2007EF11.25000
Aug 10, 2006F00.23000
Nov 12, 2005F11.04500
Jul 24, 2005F00.55000
Sep 5, 2004F00.52500
Apr 17, 2002F00.54000
Jun 18, 2001F00.23000
Apr 11, 2001F12.07500
Jul 26, 2000F13.64000
May 27, 1999F00.12000
May 16, 1999F00.12000
May 16, 1999F222.59000
Jul 6, 1998F00.23000
Jun 29, 1998F211.06000
May 28, 1998F00.23000
May 28, 1998F00.33000
May 15, 1998F00.13000
May 15, 1998F12.55000
Apr 6, 1998F00.23000
Apr 6, 1998F00.23000
Jul 16, 1996F00.22500
May 27, 1995F222.510000
May 27, 1995F12.55000
May 27, 1995F430.025010
May 27, 1995F436.040000
Oct 6, 1994F12.03000
Aug 18, 1993F12.04000
Jul 8, 1993F00.23000
Jul 8, 1993F00.12000
Jun 29, 1993F00.22300
Jun 29, 1993F00.23000
Apr 26, 1991F37.715000
Apr 27, 1989F115.06000
Jun 29, 1986F21.05000
Apr 26, 1984F00.510000
Apr 26, 1984F222.020000
May 27, 1983F11.02000
May 29, 1980F10.13000
Jul 30, 1979F123.010000
Jun 25, 1978F00.11000
Sep 23, 1977F11.01000
May 18, 1977F11.02000
May 4, 1977F11.03000
Aug 11, 1976F22.010000
Jul 3, 1974F00.11000
Apr 19, 1973F11.030000
Jun 7, 1972F21.020000
Jun 7, 1972F22.020000
Jun 6, 1971F12.010000
Sep 26, 1969F11.020000
Jul 26, 1969F211.11000
Jul 16, 1969F11.920000
Jun 28, 1969F24.320000
May 15, 1968F12.025010
Sep 7, 1965F21.010000
May 15, 1965F20.55000
May 15, 1965F20.55000
May 7, 1964F22.020000
May 5, 1960F213.815000
May 4, 1959F24.110000
Jul 4, 1957F10.11010
May 30, 1957F00.11000
May 6, 1955F215.520000
Jun 9, 1954F49.944001
Apr 5, 1954F25.188010
  1. Injuries and deaths are for the tornado’s whole path, which may extend beyond this area.
  2. 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

No tropical storm or hurricane has tracked within 100 miles since records began in 1851.

Wildfire and smoke

No large wildfire has been mapped within 25 miles since satellite mapping began in 1984.

Smoke overhead

Smokiest year

2023: 66 days

Heavy smoke on 28 days in 2021, the most of any year.

Last 10 years

28.4 days a year

Medium or heavy smoke, 2016 to 2025.

2025

21 days

Medium or heavy smoke. 40 so far in 2026.

Days with medium or heavy smoke overhead, by year 2011: 15 2012: 22 2013: 22 2014: 10 2015: 22 2016: 4 2017: 13 2018: 21 2019: 9 2020: 30 2021: 53 2022: 25 2023: 66 66 2024: 42 2025: 21 201120122013201420152016201720182019202020212022202320242025
Days each year on which a satellite-traced plume of medium or heavy smoke covered the city centre, 2011 to 2025.
  1. 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

13 federal flood insurance claims since 1993, with $360,000 paid.

Flood insurance figures are for Carroll County, the county that contains Carroll.

Federal flood insurance claims by year
Claims per year since 1993. Years with fewer than five claims are not shown.

Claims by ZIP code

Flood insurance claims by ZIP code
514558$306,000

Flood events since 1996

  • Flood45
  • Heavy Rain42
  • Flash Flood16

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.

Drought

In severe drought or worse for 163 of 1,581 months since 1895 (10%); the longest spell lasted 24 months.

The drought index is for Carroll County, the county that contains Carroll.

163

Months in severe drought or worse since 1895

62

Months in extreme drought

10%

Share of all months, severe or worse

37

Drought reports to the Weather Service since 1996

Lowest reading

June 1934

−6.62, extreme drought

Longest severe spell

24 months

June 1933 to May 1935.

Latest month

September 2026

+1.18, slightly wet

Last severe month: October 2024.

Months in severe drought or worse, by year 1895: 0 1896: 0 1897: 1 1898: 0 1899: 0 1900: 0 1901: 1 1902: 0 1903: 0 1904: 0 1905: 0 1906: 0 1907: 0 1908: 0 1909: 0 1910: 1 1911: 3 1912: 0 1913: 0 1914: 0 1915: 0 1916: 0 1917: 0 1918: 1 1919: 0 1920: 0 1921: 0 1922: 0 1923: 0 1924: 0 1925: 0 1926: 0 1927: 0 1928: 0 1929: 0 1930: 4 1931: 8 1932: 0 1933: 7 1934: 12 12 1935: 8 1936: 6 1937: 7 1938: 3 1939: 2 1940: 3 1941: 0 1942: 0 1943: 0 1944: 0 1945: 0 1946: 0 1947: 1 1948: 0 1949: 0 1950: 0 1951: 0 1952: 0 1953: 3 1954: 3 1955: 4 1956: 12 1957: 4 1958: 0 1959: 0 1960: 0 1961: 0 1962: 0 1963: 0 1964: 2 1965: 0 1966: 0 1967: 3 1968: 1 1969: 0 1970: 0 1971: 0 1972: 0 1973: 0 1974: 0 1975: 0 1976: 4 1977: 7 1978: 0 1979: 0 1980: 1 1981: 9 1982: 0 1983: 0 1984: 0 1985: 0 1986: 0 1987: 0 1988: 0 1989: 0 1990: 0 1991: 0 1992: 0 1993: 0 1994: 0 1995: 0 1996: 0 1997: 0 1998: 0 1999: 0 2000: 5 2001: 1 2002: 0 2003: 0 2004: 0 2005: 0 2006: 0 2007: 0 2008: 0 2009: 0 2010: 0 2011: 0 2012: 6 2013: 3 2014: 3 2015: 0 2016: 0 2017: 0 2018: 0 2019: 0 2020: 5 2021: 8 2022: 3 2023: 6 2024: 2 2025: 0 18951905191519251935194519551965197519851995200520152025
Months each year with a Palmer index of −3 or lower, 1895 to 2025. Twelve means the whole year.
  1. 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

No earthquake of magnitude 2.5 or more is recorded within 50 miles of the city centre in the USGS catalogue, which begins in 1900.

Severe weather and other events

691 events in the National Weather Service record for Carroll County, 627 of them since 1996.

77

Hail reports, 1 inch or larger

6

Hail, 2 inches or larger

190

Damaging gusts, 58 mph+

80

Winter weather events since 1996

4

Heat events since 1996

27

Cold events since 1996

Largest hail

May 22, 2004

2.75 inches

Strongest measured or estimated gust

July 10, 2002

96 mph

More event types since 1996

Other Storm Events types since 1996
Lightning701Aug 8, 2010

Costliest events since 1996

  1. Aug 1, 2003Drought, Carroll$12.7 million
    National Weather Service narrative

    Dry weather settled in over Iowa during the month. The last widespread rain occurred on 09 July. With the increasingly dry conditions became a primary concern as the month progressed. An extended period of heat and humidity from the 15th to 25th saw highs into the 90s to over 100 degrees F. in some locations. By month's end drought indices had worsened to severe to extreme drought across south central Iowa and at least moderate drought over the remainder of the HSA. Waterloo had its driest August on record, Des Moines its 3rd driest and Ottumwa its 8th driest. A cold front brought only a brief respite from the intense heat, as temperatures rebounded into the 90s to near 100…

  2. Jan 20, 2010Ice Storm, Carroll$2.0 million
    National Weather Service narrative

    A strong push of warm air aloft took place over the central U.S. with 850 mb temperatures warming well above zero C over much of the state. During the day on the 19th a relatively strong high moved southeast to the east of Iowa. The easterly flow of cool air in the low levels established a strong inversion over the state. Surface temperatures fell into the teens and 20s in the cool easterly flow. A strong weather system from the southwest U.S. moved east across the southern half of the country during the night of the 19th into the daytime hours of the 20th. The low passed south of Iowa, however a strong push of warm and moist air moved into Iowa during the early morning of the…

  3. Dec 23, 2009Ice Storm, Carroll$2.0 million
    National Weather Service narrative

    Part 1 of 2: A major winter storm system affected the central U.S. during Christmas week. There were two upper level systems involved with this storm. The southern stream low dove into the southern U.S. and then turned northeast. The turn was sharper than is typical as the northern stream upper low pushed southeast. The southern stream and polar low interacted with each other, resulting in a Fuji Wara effect. The southern low turned north, then eventually northwest and moved from northern Louisiana into Iowa. This resulted in a considerable amount of warm air being drawn north over Iowa. Cold air remained in place at the surface due to an existing deep snow cover over most of the…

  4. Jul 10, 2002Thunderstorm Wind$1.5 million
    National Weather Service narrative

    The airmass over Iowa was quite unstable during the predawn hours of the 10th with surface dew points in the 70s. In spite of the fact that a weak cold front had passed through the state, little drying of the atmosphere took place. An unseasonably strong upper level closed low pressure system moved southeast across North Dakota into west central Minnesota during the morning hours of the 10th. Several lines of thunderstorms formed over southeast South Dakota into northwest Iowa and moved southeast from there. The storms produced very heavy rainfall during the initial round of storms along with winds of 40 to 50 MPH. The thunderstorms formed into a well developed MCS by dawn with…

  5. Nov 10, 1998High Wind, Carroll$300,000
    National Weather Service narrative

    Iowa experienced the worst November storm system since the great storm of 9 and 10 November 1975. During the 9th, low pressure developed over southeast Colorado. The low moved across Kansas during the afternoon and evening of the 9th and deepened to about 990 mb. Warm and moist air was drawn north ahead of the low resulting in widespread across the state. Thunderstorms erupted during the late evening of the 9th, though no severe weather occurred. During the predawn hours of the 10th, a jet streak rotated around the base of the upper level low pressure area. The jet stream, combined with a tropospheric fold, resulted in explosive deepening of the low. As the low moved through…

  6. May 24, 1996Lightning$300,000
    National Weather Service narrative

    Thunderstorms passed over Carroll County during the early morning hours. Though they weren't severe, lightning caused major damage when a church was struck. A church in Lidderdale was set on fire and destroyed after being struck by lightning.

  7. Jul 17, 1996Flash Flood$300,000
  8. Jun 29, 1998Thunderstorm Wind$250,000
    National Weather Service narrative

    A complex weather situation was set up over the central U.S. as a mesoscale convective system passed to the south of Iowa during the overnight hours and early morning of the 29th. Initially, the surface warm front was located to the south of this system. That was not actually the case aloft however. During the predawn hours the surface front surged north and by sunrise was located across northeast Nebraska across northern Iowa. The airmass was very unstable to the south of the front with dew point temperatures will in the 70s F. The initial development of thunderstorms took place during the early part of the day over northeast Nebraska. The storms became severe quickly as they…

  9. Apr 25, 2007Flood$250,000
    National Weather Service narrative

    A strong low pressure developed over eastern Colorado and moved southeast into northern Oklahoma by the 24th. Deep moisture was pulled north ahead of the low with surface dew points in the low 70s reaching northern Oklahoma. Strong isentropic lift took place over the Des Moines CWA and resulted in a large and sustained area of rain and embedded thunderstorms. Rainfall of two to over five inches of rainfall occurred over a large part of the CWA, with isolated amounts in the six to seven inch range over a 2 day period. This event brought about the flash flooding event of the evening of the 24th. The situation transitioned into a general areal flood event on the 25th, with several…

  10. May 6, 2007Flood$250,000
    National Weather Service narrative

    A very strong upper level low pressure trough had carved out over the western U.S. Iowa was in the strong southwest flow on the front side of this system. A surface warm front lifted north into southwest Iowa during the evening of the 5th. The airmass became quite unstable with plenty of deep moisture advection into the areas. Precipitable water values were in the 1.5 to 1.75 inch range by midnight. The lifted index fell to the -6 to -8 C. There was a reasonable amount of CAPE available with about 2500 J/kg at the onset of the event. The LCL was around 1000 meters and the freezing level was a relatively high 13,500 feet. With the warm front in the vicinity, there was a…

  1. 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 Carroll, 0.8 miles from the city centre, with records from 1893.

All-time high
112°F2 times, most recently Jul 4, 1936
All-time low
−40°FJan 12, 1912
Warmest night
81°FJul 14, 1901
Coldest day
−15°F2 times, most recently Feb 2, 1917
Wettest day
6.87 inJul 10, 1993
Snowiest day
18.0 inJan 29, 1947
Hottest year
1931mean 52.9°F
Coldest year
1917mean 43.7°F
Wettest year
201551.37 in
Driest year
198014.56 in
Snowiest season
57.0 in1959-60
Average monthly high and low temperature and precipitation, last 30 years, Carroll 32°F 29° 11° 0.8 Jan 33° 13° 1.1 Feb 47° 25° 1.9 Mar 61° 36° 3.1 Apr 72° 49° 4.5 May 82° 60° 4.9 Jun 85° 64° 4.1 Jul 83° 61° 4.0 Aug 77° 52° 2.7 Sep 64° 40° 2.6 Oct 48° 27° 1.3 Nov 34° 16° 1.3 Dec Precipitation, inches
Average daily high and low by month, and average monthly precipitation, over the last 30 years.
Nights at or below freezing per year 1976: 160 1978: 146 1979: 160 1980: 168 1981: 143 1982: 149 1983: 154 1984: 136 1985: 153 1986: 144 1987: 150 1988: 169 1989: 165 1990: 158 1991: 146 1992: 143 1993: 163 1994: 145 1995: 147 1996: 165 1997: 156 1998: 118 1999: 141 2000: 136 2001: 143 2002: 156 2003: 151 2004: 145 2005: 153 2006: 156 2007: 150 2008: 165 2009: 155 2010: 151 2011: 160 2012: 141 2013: 175 175 2014: 159 2015: 127 2016: 132 2017: 137 2018: 162 2019: 152 2020: 154 2021: 142 2022: 169 2023: 154 2024: 142 2025: 135 19761987199720072017
Nights at or below freezing each complete year, last 50 years. Thirty-year average: 149.4.
Snowfall by winter 1976: 17.6 in 1978: 40.2 in 1979: 25.7 in 1980: 16.8 in 1981: 48.8 in 1982: 53.5 in 1983: 54.9 in 54.9 1984: 34.1 in 1985: 31.0 in 1986: 21.0 in 1987: 18.0 in 1989: 19.2 in 1990: 32.0 in 1991: 3.0 in 1992: 34.9 in 1993: 27.9 in 1994: 24.0 in 1995: 24.5 in 1996: 41.2 in 1997: 43.6 in 1998: 46.3 in 1999: 28.2 in 2000: 35.5 in 2001: 12.5 in 2002: 32.2 in 2003: 54.9 in 2004: 15.6 in 2005: 22.0 in 2006: 45.9 in 2007: 29.3 in 2008: 31.9 in 2009: 42.6 in 2013: 26.1 in 2014: 26.7 in 2015: 34.9 in 2016: 21.1 in 2017: 32.4 in 2018: 33.0 in 2019: 20.4 in 2020: 39.7 in 2021: 15.6 in 2022: 30.3 in 2023: 21.7 in 2024: 27.5 in 2025: 18.1 in 19761987199820082021
Total snowfall each winter (July to June), last 50 winters.

Median first snow

November 21

Earliest: October 15, 2018

Median last snow

March 28

Latest: May 29, 1947

0 of 95 winters had no measurable snow.

Station Carroll (USC00131233), 1,240 ft elevation, 0.8 miles from the city centre. Daily records from 1893 to October 28, 2026; 97.8% 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

16 since 1953. The most recent: Covid-19 Pandemic, March 23, 2020.

Declarations for Carroll County.

Federal disaster declarations
Mar 23, 2020BiologicalCovid-19 PandemicMajor disasterDR-4483-IA
Mar 13, 2020BiologicalCovid-19EmergencyEM-3480-IA
Mar 23, 2019FloodSevere Storms and FloodingMajor disasterDR-4421-IA
Mar 2, 2010Severe StormSevere Winter StormMajor disasterDR-1880-IA
Feb 25, 2010Severe StormSevere Winter Storms and SnowstormMajor disasterDR-1877-IA
May 27, 2008Severe StormSevere Storms, Tornadoes, and FloodingMajor disasterDR-1763-IA
Mar 30, 2007SnowstormSnowEmergencyEM-3275-IA
Sep 10, 2005HurricaneHurricane Katrina EvacuationEmergencyEM-3239-IA
May 25, 2004Severe StormSevere Storms, Tornadoes, and FloodingMajor disasterDR-1518-IA
Jul 2, 1998FloodSevere Storms, Tornadoes and FloodingMajor disasterDR-1230-IA
Jul 9, 1993FloodSevere Storms & FloodingMajor disasterDR-996-IA
Dec 26, 1991Severe Ice StormIce StormMajor disasterDR-928-IA
May 26, 1990FloodSevere Storms & FloodingMajor disasterDR-868-IA
Jun 24, 1974FloodSevere Storms & FloodingMajor disasterDR-443-IA
Apr 25, 1969FloodFloodingMajor disasterDR-259-IA
Apr 22, 1965FloodFloodingMajor disasterDR-193-IA

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.

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 USC00131233.
  • 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.