Jasper County

Every recorded tornado

1. Injuries and deaths are for the tornado’s whole path, which may extend beyond the county. Deaths recorded within Jasper County: 2.
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.

Claims by ZIP code

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

River gauges

1. 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.

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.

More event types since 1996

Costliest events since 1996

1. Mar 5, 2022Tornado$50.0 million
   National Weather Service narrative

   The tornado moved into Jasper county from Polk county. The tornado remained largely in rural areas for much of its path across Jasper county. Despite its rural venture, the tornado impacted several residences in western Jasper county producing several areas of EF2 damage. The tornado did pass not far from the southeast side of Colfax damaging structures near the intersection of Highway 117 and S 44th Avenue West. The tornado crossed Interstate 80 east of Colfax near mile marker 160 and then proceeded towards Newton, grazing both the communities of Lambs Grove and Newton on the north sides. Most of the damage was to trees and minor damage to structures including loss of shingles…

2. Aug 1, 2003Drought, Jasper$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…

3. Mar 9, 2002Thunderstorm Wind$1.5 million
   National Weather Service narrative

   As the storm system mentioned above lifted out of the southern Plains a line of thunderstorms formed near the strong frontal boundary. Strong divergence aloft combined with increasing instability resulted in rapid development of linear thunderstorms. Several bow elements were embedded in the line as well. Most of the storms produced hail, and in some cases enough to cover the ground. The hail was small with mostly pea size being reported. High were were the main feature with the storms. Numerous reports of 60 to 80 MPH winds were received. Structural damage was reported with some of the storms. For example, high winds destroyed grain bins on one farm in Cass County at Massena. In…

4. Sep 30, 2007Tornado$1.0 million
   National Weather Service narrative

   Tornado moved into Jasper County from Mahaska County, then continued northeast into Poweshiek County.|

5. 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…

6. Oct 26, 1997Heavy Snow, Jasper$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…

7. Feb 24, 2007Winter Storm, Jasper$500,000
   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…

8. Jul 7, 2003Hail$500,000
   National Weather Service narrative

   A nearly stationary frontal boundary sank into Iowa during the afternoon hours of the 7th. The airmass became extremely unstable with lifted indices around -12 C. and CAPE values in excess of 6000 J/kg over the south two thirds of the state. There was little to no cap over the state by the mid day. Convergence along the front was very strong with surface dew points rising into the upper 70s to low 80s over a large part of central Iowa by mid afternoon. Dew points at the 850 mb level were 20 C. As a result once thunderstorms began to form the development was explosive. Within 30 minutes a severe super formed in central Iowa east of Des Moines. The storms produced very large hail…

9. Mar 5, 2022Tornado$500,000
   National Weather Service narrative

   This tornado developed from the same supercell that produced the Winterset to Newton tornado. It remained in rural areas of central and eastern Jasper county downing power poles and trees along its path. Machine sheds were destroyed at a residence along East 116th Street North with additional damage to outbuildings along East 132nd Street North. The tornado passed just west and north of the hamlet of Newburg before exiting the county into Poweshiek county just south of North 99th Avenue East.

10. Jul 7, 2003Hail$500,000
    National Weather Service narrative

    A nearly stationary frontal boundary sank into Iowa during the afternoon hours of the 7th. The airmass became extremely unstable with lifted indices around -12 C. and CAPE values in excess of 6000 J/kg over the south two thirds of the state. There was little to no cap over the state by the mid day. Convergence along the front was very strong with surface dew points rising into the upper 70s to low 80s over a large part of central Iowa by mid afternoon. Dew points at the 850 mb level were 20 C. As a result once thunderstorms began to form the development was explosive. Within 30 minutes a severe super formed in central Iowa east of Des Moines. The storms produced very large hail…

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

107°F2 times, most recently Aug 3, 1930

All-time low

−35°F2 times, most recently Feb 4, 1996

Warmest night

84°F2 times, most recently Jul 31, 1917

Coldest day

−13°FFeb 3, 1996

Wettest day

6.92 inAug 5, 1970

Snowiest day

12.0 in3 times, most recently Dec 9, 2009

Hottest year

1922mean 52.2°F

Coldest year

1979mean 44.2°F

Wettest year

201057.51 in

Driest year

198817.53 in

Snowiest season

63.3 in1978-79

Station Grinnell 3 Sw (USC00133473), 915 ft elevation, 16.8 miles from the population centre. Daily records from 1893 to October 27, 2026; 91.0% 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 USC00133473.
• 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.