Davis County

Every recorded tornado

1. Injuries and deaths are for the tornado’s whole path, which may extend beyond the county. Deaths recorded within Davis County: 0.
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.

Smoke overhead

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.

OpenFEMA NFIP Redacted Claims v3, refreshed August 4, 2026. NOAA Storm Events through 2026.

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.

Every earthquake of magnitude 4 or more within 50 miles

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.

More event types since 1996

Costliest events since 1996

1. Aug 1, 2003Drought, Davis$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. Apr 6, 1997High Wind, Davis$1.8 million
   National Weather Service narrative

   The storm system that moved through Iowa the day before was located to the north of the state on the morning of the 6th. High winds developed in the wake of the deepening storm system. Central pressure of the storm was below 975 mb at the time. Winds of 30 to 45 MPH overspread the state during the early morning hours and became gusty by mid day. Gusts were frequently above 55 MPH and in some cases over 60 MPH. The high winds persisted through much of the day. Damage was widespread around the state. There were numerous reports of damage to trees, powerlines, and out buildings. There were also a few reports of overturned high profile vehicles. Some of the higher gusts included a 62…

3. Apr 10, 1997Heavy Snow, Davis$1.6 million
   National Weather Service narrative

   A strong baroclinic frontal boundary formed to the south of Iowa during the night of the 9th and morning of the 10th. Warm air riding north on a southern flow in the low levels of the atmosphere over ran cold air at the surface. Wind speeds in the low level jet were between 50 and 65 MPH. The frontal boundary moved north very little as a strong Arctic high pressure cell nearly 1040 mb in strengh remained poised to the north of Iowa. Snow broke out during the predawn hours of the 10th. At first accumulations were not very heavy. Thunderstorms formed over Kansas and moved rapidly northeast into Iowa. Snowfall rates picked up with heavy snow over the southern part of the state by the…

4. Jun 7, 2009Thunderstorm Wind$1.0 million
   National Weather Service narrative

   KMEM Radio reported that the Davis County Courthouse and several businesses had shattered windows and a local high school had a partial roof collapse. Damage was caused by combination of wind and hail.

5. Feb 18, 1997Flood, Davis$750,000
   National Weather Service narrative

   Iowa was under a deep snow pack with water equivalents ranging from around an inch over the south third of the state to around 5 inches across the north. A strong warming trend took place as cold air over Iowa was replaces with Chinook air from the Rockies. Rapid melting of the snow pack took place with as much as 11 inches melting in just one day on the 19th. Though the warming began on the 18th, the bulk of the melt took place the next day. Early in the flooding event, flooding was caused as ice choked rivers were unable to handle runoff. Flooding took place in the upper reaches of many of the states rivers. By the afternoon of the 19th, flooding was taking place along many of…

6. Apr 25, 1996High Wind, Davis$750,000
   National Weather Service narrative

   A very intense low pressure system moved to the north of Iowa. It actually passed over northern Minnesota and was near 980 mb central pressure. From the low a cold front extended south. As it passed through Iowa, strong subsidence combined with the tight pressure gradient produced strong winds. The strong winds entered northwest Iowa during the morning hours. The winds continued into the evening hours as an Arctic front pushed south across the state. The high winds spread east and south across the state during the day, reaching the southeast part of Iowa around mid afternoon. Winds were sustained 30 to 35 MPH with frequent gusts to near 60 MPH. By late afternoon the winds produced…

7. Jan 15, 1997Cold/Wind Chill, Davis$750,000
   National Weather Service narrative

   During the night of the 14th into the morning of the 15th a low pressure tracked east, then northeast across the central U.S. The low passed south of Iowa, leaving behind a fresh 2 to 5 inches of fluffy snow. There was no wind associated with this snowfall. On the 15th, an Arctic cold front dropped south out of Canada. It entered northwest Iowa during the mid afternoon hours and quickly swept southeast across the state. Behind in was sharply colder temperatures and very strong northwest winds. High winds moved into north central Iowa with wind gusts of 62 MPH recorded at Estherville in Emmet County and Emmetsburg in Palo Alto County. Sustained winds in those areas were between 45…

8. Jan 26, 1996Heavy Snow, Davis$600,000
9. Apr 8, 1999Tornado$550,000
   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…

10. Aug 24, 2007Flash Flood$500,000
    National Weather Service narrative

    Four feet of water was reported with a car stranded on the road. Water was backing up into basements. Gravel roads countywide reportedly had washouts with many shoulder washouts.

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.

All-time high

106°FJul 23, 2012

All-time low

−27°FFeb 3, 1996

Warmest night

84°FAug 17, 1983

Coldest day

−14°FFeb 2, 1996

Wettest day

5.32 inSep 14, 1992

Snowiest day

15.0 inFeb 13, 1978

Hottest year

1987mean 54.3°F

Coldest year

2014mean 47.8°F

Wettest year

199854.52 in

Driest year

195319.09 in

Snowiest season

63.9 in1977-78

Station Ottumwa Ind Airport (USW00014950), 834 ft elevation, 23.4 miles from the population centre. Daily records from 1948 to October 16, 2026; 98.9% 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.

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.

Neighbouring counties

• 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 USW00014950.
• 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.