Adams County

Population 3,617 (2025) 423 sq mi

Adams County has recorded 28 tornadoes since 1950, 71st most of 99 counties in Iowa; the most recent was on May 21, 2024.

Hazard fingerprint for Adams County Tornado: 81th percentile. Tropical: 0th percentile. Wildfire: 0th percentile. Flood: 72th percentile. Hail & wind: 54th percentile. Heat: 25th percentile. Cold: 73th percentile. Winter: 45th 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 since 195028

At a glance

The record for Adams County in eight numbers. Each links to its section below.

Tornadoes since 1950

28

71st of 99 in Iowa

Fewer than the typical Iowa county, which has had 35

Details

Flood insurance claims

6

72nd of 99 in Iowa

$221,000 paid since 2008

Details

Strongest tornado

F4

April 8, 1999, 49.0 mile path

Federal disaster declarations

17

Most recent: Severe Storms, Tornadoes, and Flooding, 2024

Details

Record high

107°F

July 5, 1911

Details

Record low

−34°F

January 12, 1912

Details

Snowiest season

61.0in

Winter of 1911-12

Costliest event since 1996

$12.7M

Drought, August 1, 2003

Details

Tornadoes

About one every 2.7 years since 1950, 6 of them rated F3/EF3 or stronger.

Strongest

April 8, 1999

F4, 49.0 mile path

1,000 yards wide.

Deadliest

May 21, 2024

5 killed, EF4

35 injured along the whole path.

Most recent

Tuesday, May 21, 2024

EF1, 12.7 mile path

2 years ago.

Tornadoes by decade Doppler radar era² 1950s: 3 3 1960s: 0 1970s: 0 1980s: 4 4 1990s: 3 3 2000s: 4 4 2010s: 6 6 2020s: 8 8 1950s1960s1970s1980s1990s2000s2010s2020s
Recorded tornadoes per decade. The 2020s are incomplete.
Tornadoes by month J: 0 F: 0 M: 4 A: 6 M: 6 J: 7 7 J: 3 A: 2 S: 0 O: 0 N: 0 D: 0 JFMAMJJASOND
By month of occurrence, all years.

Every recorded tornado

Tornadoes in Adams County since 1950
May 21, 2024EF112.720000
May 21, 2024EF440.61,600355
May 21, 2024EF333.91,30000
Apr 26, 2024EF29.735000
Apr 16, 2024EF02.45000
Mar 5, 2022EF02.810000
Mar 5, 2022EFU1.54000
Mar 28, 2020EF17.511500
Jun 28, 2017EF01.93000
Jun 28, 2017EF13.810000
Aug 2, 2015EF15.030000
Apr 14, 2012EF216.680020
May 11, 2011EF00.43000
Mar 22, 2011EF03.18000
Jun 4, 2008EF15.615000
Jun 4, 2008EF19.515000
Jun 4, 2008EF02.37500
Apr 8, 2001F11.05010
Jul 16, 1999F00.1000
Apr 8, 1999F449.01,00030
Jul 24, 1993F00.22000
May 24, 1989F449.01,76000
Aug 22, 1988F14.25000
Jun 7, 1984F325.010030
Jun 14, 1981F00.11000
May 18, 1959F21.020000
Jul 14, 1958F314.810010
Apr 25, 1957F00.110000
  1. Injuries and deaths are for the tornado’s whole path, which may extend beyond the county. Deaths recorded within Adams County: 1.
  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 here since satellite mapping began in 1984.

Smoke overhead

Smokiest year

2023: 66 days

Heavy smoke on 26 days in 2021, the most of any year.

Last 10 years

26.4 days a year

Medium or heavy smoke, 2016 to 2025.

2025

20 days

Medium or heavy smoke. 40 so far in 2026.

Days with medium or heavy smoke overhead, by year 2011: 14 2012: 20 2013: 19 2014: 8 2015: 18 2016: 2 2017: 12 2018: 16 2019: 9 2020: 28 2021: 52 2022: 25 2023: 66 66 2024: 34 2025: 20 201120122013201420152016201720182019202020212022202320242025
Days each year on which a satellite-traced plume of medium or heavy smoke covered the county’s population 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

6 federal flood insurance claims since 2008, with $221,000 paid.

Federal flood insurance claims by year 2008: 5 5 2008
Claims per year since 2008. Years with fewer than five claims are not shown.

Most claims in one year

2008: 5 claims

$213,000 paid.

Claims by ZIP code

Flood insurance claims by ZIP code
508415$49,000

Flood events since 1996

  • Flash Flood26
  • Heavy Rain25
  • Flood14

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 148 of 1,581 months since 1895 (9%); the longest spell lasted 29 months.

148

Months in severe drought or worse since 1895

84

Months in extreme drought

9%

Share of all months, severe or worse

27

Drought reports to the Weather Service since 1996

Lowest reading

August 1934

−7.95, extreme drought

Longest severe spell

29 months

May 1955 to September 1957.

Latest month

September 2026

+3.51, very wet

Last severe month: October 2003.

Months in severe drought or worse, by year 1895: 0 1896: 0 1897: 2 1898: 0 1899: 0 1900: 0 1901: 0 1902: 0 1903: 0 1904: 0 1905: 0 1906: 0 1907: 0 1908: 0 1909: 0 1910: 0 1911: 6 1912: 1 1913: 0 1914: 1 1915: 0 1916: 0 1917: 2 1918: 9 1919: 0 1920: 0 1921: 0 1922: 0 1923: 0 1924: 0 1925: 0 1926: 0 1927: 0 1928: 1 1929: 0 1930: 0 1931: 0 1932: 0 1933: 3 1934: 12 12 1935: 8 1936: 6 1937: 5 1938: 12 1939: 10 1940: 5 1941: 0 1942: 0 1943: 0 1944: 0 1945: 0 1946: 0 1947: 0 1948: 0 1949: 0 1950: 0 1951: 0 1952: 0 1953: 3 1954: 10 1955: 9 1956: 12 1957: 9 1958: 0 1959: 0 1960: 0 1961: 0 1962: 0 1963: 0 1964: 2 1965: 0 1966: 0 1967: 0 1968: 0 1969: 0 1970: 0 1971: 0 1972: 0 1973: 0 1974: 0 1975: 0 1976: 0 1977: 2 1978: 0 1979: 0 1980: 0 1981: 0 1982: 0 1983: 0 1984: 0 1985: 0 1986: 0 1987: 0 1988: 7 1989: 8 1990: 0 1991: 0 1992: 0 1993: 0 1994: 0 1995: 0 1996: 0 1997: 0 1998: 0 1999: 0 2000: 2 2001: 0 2002: 0 2003: 1 2004: 0 2005: 0 2006: 0 2007: 0 2008: 0 2009: 0 2010: 0 2011: 0 2012: 0 2013: 0 2014: 0 2015: 0 2016: 0 2017: 0 2018: 0 2019: 0 2020: 0 2021: 0 2022: 0 2023: 0 2024: 0 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

2 earthquakes of magnitude 2.5 or more within 50 miles since 1995; none reached magnitude 4.

0

Magnitude 2.5+ inside the county since 1973

2

Magnitude 3+ within 50 miles since 1973

0

Magnitude 4+ within 50 miles since 1900

0

Magnitude 5+ within 50 miles since 1900

Largest within 50 miles

July 16, 2004

Magnitude 3.5

6 km SSE of Riverton, Iowa; 37.4 miles away, 3.1 miles deep.

Most recent, magnitude 3 or more

July 16, 2004

Magnitude 3.5

6 km SSE of Riverton, Iowa; 37.4 miles away.

  1. 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).
  2. 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

424 events in the National Weather Service record, 399 of them since 1996.

70

Hail reports, 1 inch or larger

5

Hail, 2 inches or larger

74

Damaging gusts, 58 mph+

62

Winter weather events since 1996

4

Heat events since 1996

23

Cold events since 1996

Largest hail

May 19, 2013

3.00 inches

Strongest measured or estimated gust

July 14, 1987

81 mph

More event types since 1996

Other Storm Events types since 1996
Lightning100Jun 3, 2014

Costliest events since 1996

  1. Aug 1, 2003Drought, Adams$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. May 21, 2024Tornado$1.8 million
    National Weather Service narrative

    The tornado entered into Adams County after clipping the northwest corner of Taylor County. Damage was immediate on the county border with damage to trees and and to farm buildings and power poles within the first few miles in the county. The tornado continued to gain in strength and size as it travelled northeast through southwest Adams county remaining in rural areas south and east of Nodaway. The tornado eventually crossed Federal Highway 34 just north of Brooks with plenty of videos showing a large funnel with debris swirling below it. As the tornado crossed State Highway 148, it gained in strength with EF2 damage becoming more common. Upon reaching the intersection of 150th…

  3. Apr 8, 1999Tornado$1.0 million
    National Weather Service narrative

    As mentioned in the narrative above, an intense low pressure formed to the southwest of Iowa. The low tracked northeast and lifted into eastern Nebraska. Ahead of the low, a strong low level jet of around 60 knots continued through the day. A nearly stationary frontal boundary extended east from the low. It lifted into southeast Nebraska during the day, but made little progress into southern Iowa. Lines of thunderstorms formed along the boundary through the day and lifted north rapidly. These storms were elevated in nature and as a result produced most of their severe weather in the form of hail. As the day unfolded, a sharp dry line was clearly evident on the satellite as early…

  4. May 21, 2024Tornado$1.0 million
    National Weather Service narrative

    The tornado entered into Adams County from Montgomery County. This tornado remained in rural areas of western and northern Adams County until lifting north of the town of Carl near the Adair County line. The tornado impacted a house on the north side of 200th street shortly after entering the county removing much of the roof with general collapse of the structure. A large hog confinement facility near the intersection of 190th and Aspen was severally damage with most buildings destroyed. EF3 damage occurred to a house along 175th Street near Cherry Avenue with all wall removed except a couple of the interior walls. The outbuildings at this location were all destroyed as well.…

  5. Oct 26, 1997Heavy Snow, Adams$640,000
    National Weather Service narrative

    The first major winter storm of the season developed over the central Rockies as a powerful upper level jet stream dove into the southern Rockies. Intense low pressure developed over northern Oklahoma, then drifted northeast on the early morning of the 26th. A cold high pressure of Arctic origin was poised to the north of Iowa. The high gradually pushed cold air south into the central U.S. causing the precipitation on the northwest edge of the storm system to change to snow. During the early morning hours, the system went convective with widespread "thundersnow" reported over the south half of Iowa. Lightning struck a tree outside of a house in Nevada causing damage to electrical…

  6. Nov 10, 1998High Wind, Adams$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…

  7. Sep 7, 2001Thunderstorm Wind$250,000
    National Weather Service narrative

    Two distinct boundaries were in place across Iowa. A cold front had slipped into the northwest part of the state and nearly bisected the state by the early evening hours. Meanwhile, an east-northeast to west-southwest boundary was in place across the central part of the state. The second boundary was left in place by the convection that occurred earlier in the day. The airmass remained quite unstable during the evening with dew point temperatures in the mid 60s to around 70. Colder air continued to slip into the state aloft with the freezing level falling just below 12,000 feet by the early evening. Another round of thunderstorms fired to the southwest of Iowa and moved into the…

  8. Jul 29, 2015Flood$250,000
    National Weather Service narrative

    Flooding was reported across much of the county with water affecting roads and low lying areas. Numerous secondary roads across the county remain closed with water flowing over them.

  9. Feb 24, 2007Winter Storm, Adams$250,000
    National Weather Service narrative

    A major winter storm affected Iowa through the 24th and 25th of February. A powerful upper low moved onto the west coast during the middle of the week, and advanced east through the Rockies during the end of the week. Strong warm air advection took place over the top of a shallow polar airmass that was in place over Iowa. The east-southeasterly flow at the surface drew cool and dry air into the state from the east, setting the stage for a significant ice storm. The main area of precipitation overspread the state during the early morning hours of the 24th and persisted through much of the 25th. Initially, very warm air aloft meant that the precipitation fell in the form of freezing…

  10. May 11, 2011Flash Flood$200,000
    National Weather Service narrative

    Several places throughout Nodaway reported 6 inches of flowing water over roads and inundating homes and businesses.

  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 Greenfield, 24.1 miles from the county’s population centre, with records from 1893.

All-time high
107°FJul 5, 1911
All-time low
−34°FJan 12, 1912
Warmest night
84°FJul 7, 1980
Coldest day
−15°F3 times, most recently Dec 24, 1983
Wettest day
8.00 inSep 15, 1992
Snowiest day
12.0 in3 times, most recently Jan 4, 1971
Hottest year
1921mean 53.5°F
Coldest year
1893mean 46.8°F
Wettest year
201456.01 in
Driest year
196618.15 in
Snowiest season
61.0 in1911-12
Average monthly high and low temperature and precipitation, last 30 years, Greenfield 32°F 31° 13° 0.9 Jan 36° 16° 1.2 Feb 50° 28° 2.2 Mar 63° 38° 3.5 Apr 72° 51° 5.2 May 82° 61° 4.8 Jun 85° 65° 3.4 Jul 83° 62° 4.3 Aug 78° 55° 3.6 Sep 65° 42° 2.9 Oct 50° 29° 1.7 Nov 36° 18° 1.4 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: 142 1977: 126 1978: 144 1979: 145 1980: 142 1981: 127 1982: 128 1984: 144 1985: 137 1986: 140 1987: 123 1988: 144 1989: 144 1990: 132 1991: 134 1992: 138 1993: 149 1994: 126 1995: 134 1996: 152 1997: 147 1998: 111 1999: 123 2000: 128 2001: 131 2002: 140 2003: 128 2004: 128 2005: 134 2006: 125 2007: 134 2008: 143 2009: 137 2010: 140 2011: 144 2012: 134 2013: 167 2014: 152 2015: 125 2016: 125 2017: 127 2018: 161 2019: 153 2020: 159 2021: 138 2022: 173 173 2024: 131 2025: 136 19761987199720072017
Nights at or below freezing each complete year, last 50 years. Thirty-year average: 138.8.
Snowfall by winter 1975: 25.5 in 1976: 17.1 in 1977: 32.1 in 1978: 24.1 in 1980: 15.5 in 1981: 26.1 in 1982: 33.0 in 1983: 42.0 in 1984: 29.0 in 1985: 14.0 in 1986: 14.7 in 1987: 18.0 in 1989: 18.0 in 1990: 22.0 in 1991: 11.5 in 1992: 31.2 in 1993: 15.5 in 1994: 23.0 in 1995: 30.0 in 1996: 32.0 in 1997: 43.9 in 1998: 41.0 in 1999: 16.3 in 2000: 42.6 in 2001: 11.5 in 2002: 26.3 in 2003: 48.5 in 48.5 2004: 12.3 in 2005: 21.6 in 2006: 30.5 in 2007: 27.9 in 2008: 25.6 in 2009: 46.3 in 2012: 39.8 in 2013: 34.7 in 2014: 18.9 in 2016: 8.2 in 2017: 17.6 in 2020: 44.7 in 2021: 17.5 in 2022: 28.2 in 2023: 25.7 in 2024: 9.8 in 19751986199720072022
Total snowfall each winter (July to June), last 50 winters.

Median first snow

November 22

Earliest: October 10, 1932

Median last snow

March 24

Latest: May 9, 1945

0 of 85 winters had no measurable snow.

Station Greenfield (USC00133438), 1,316 ft elevation, 24.1 miles from the population centre. Daily records from 1893 to October 27, 2026; 98.3% 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

17 since 1953. The most recent: Severe Storms, Tornadoes, and Flooding, May 24, 2024.

Federal disaster declarations
May 24, 2024Severe StormSevere Storms, Tornadoes, and FloodingMajor disasterDR-4784-IA
Mar 23, 2020BiologicalCovid-19 PandemicMajor disasterDR-4483-IA
Mar 13, 2020BiologicalCovid-19EmergencyEM-3480-IA
Mar 23, 2019FloodSevere Storms and FloodingMajor disasterDR-4421-IA
Jul 14, 2014Severe StormSevere Storms, Tornadoes, Straight-Line Winds, and FloodingMajor disasterDR-4181-IA
Jul 29, 2010Severe StormSevere Storms, Flooding, and TornadoesMajor disasterDR-1930-IA
Mar 2, 2010Severe StormSevere Winter StormMajor disasterDR-1880-IA
May 27, 2008Severe StormSevere Storms, Tornadoes, and FloodingMajor disasterDR-1763-IA
Jan 4, 2008Severe Ice StormSevere Winter StormMajor disasterDR-1737-IA
Sep 10, 2005HurricaneHurricane Katrina EvacuationEmergencyEM-3239-IA
May 25, 2004Severe StormSevere Storms, Tornadoes, and FloodingMajor disasterDR-1518-IA
Jun 24, 1996Severe StormSevere Storms and FloodingMajor disasterDR-1121-IA
Jul 9, 1993FloodSevere Storms & FloodingMajor disasterDR-996-IA
Oct 2, 1992FloodSevere Storms & FloodingMajor disasterDR-965-IA
Dec 26, 1991Severe Ice StormIce StormMajor disasterDR-928-IA
May 23, 1973FloodSevere Storms & FloodingMajor disasterDR-386-IA
Sep 26, 1972FloodSevere Storms & FloodingMajor disasterDR-354-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.

How this compares

Where Adams County stands among 99 counties in Iowa and 3,143 in the United States.

Ranks
Tornadoes since 19502871 / 991,087 / 3,143
Tornadoes rated F3/EF3 or stronger66 / 99156 / 3,143
Tropical cyclones within 50 mi0——
Hurricane-strength passes within 50 mi0——
Wildfire acres since 19840——
Flood insurance claims672 / 992,494 / 3,143
Flood insurance paid$221,00056 / 992,096 / 3,143
Disaster declarations1770 / 992,018 / 3,143
Flood events since 19966577 / 991,096 / 3,143
Hail and wind events since 199619287 / 992,034 / 3,143
Winter storm events since 19966296 / 991,677 / 3,143
Reported damage since 1996$24.5 million57 / 991,322 / 3,143
River crests at major flood stage0——
High tide flooding days a year, last 10 years0.0——
Months in severe drought since 189514863 / 99985 / 3,143
Medium or heavy smoke days a year, last 10 years26.471 / 99486 / 3,143
Earthquakes M4+ within 50 mi since 19000——
Earthquakes M2.5+ in the county since 19730——

Neighbouring counties

Neighbouring counties
Adair County34000
Cass County430057
Montgomery County310082
Page County40003
Ringgold County29000
Taylor County40006
Union County420014

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 USC00133438.
  • 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.