Story County

Every recorded tornado

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

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. Aug 11, 2010Flood$50.0 million
   National Weather Service narrative

   Hilton Coliseum reported 4 to 6 feet of water inside flooding the stadium and basketball floor. Cy Stephens Auditorium also reports water in the mechanical building up to the 1st floor.

2. Aug 1, 2003Drought, Story$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. May 21, 2024Tornado$3.2 million
   National Weather Service narrative

   This tornado moved into Story County from Polk County. The tornado was quite wide at this point nearing 1000 yards wide at times. Along Highway 210 southeast of Cambridge, 8 large wooden and relatively new higher voltage power poles were snapped. Trees were obliterated along 315th Street east of Cambridge. Additional EF2 damage occurred 620th Avenue where numerous outbuildings were destroyed. A house was completely removed from its foundation at the intersection of 270th Street and Woods Rd and was tossed across 270th Street. However, the house was undergoing a remodel at the time and had no anchorage to the pour concrete foundation, hence the EF2 rating at this location. Damage…

4. Jun 16, 1996Flash Flood$1.5 million
5. Aug 9, 2010Flood$1.0 million
   National Weather Service narrative

   The very wet weather pattern of June and July continued into the first two weeks of August. Central Iowa was hardest hit by rainfall with three consecutive nights of torrential rains on the 8th, 9th and 10th. Ankeny recorded 9.86 inches of rain over these three nights while Ames had 9.61 inches. Record flooding impacted much of Story, Polk, Jasper and Mahaska counties. Iowa received a much needed break from the heavy rainfall for most of the second half of the month with a statewide average of only 0.91 inches between 14th and the morning of the 31st. Moderate to heavy rain fell on the night of the 31st into early September 1st over the southeast two-thirds of Iowa with the Ames…

6. Sep 1, 2018Lightning$1.0 million
   National Weather Service narrative

   A local photographer came across a smoldering wind turbine that had been struck by lightning overnight. It also had previous damage from a tornado earlier in the year.

7. Jun 17, 1996Flood, Story$1.0 million
   National Weather Service narrative

   The heavy rainfall mentioned above resulted in flooding along the Skunk River. In fact, the river crested about a foot over the all time record stage at Ames, eclipsing the infamous 1993 flood event. The flooding closed many road, caused significant damage to houses and businesses located near the river, and flooded out cropland.

8. Apr 8, 1999Tornado$800,000
   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…

9. Oct 26, 1997Heavy Snow, Story$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…

10. Nov 12, 2005Tornado$580,000
    National Weather Service narrative

    Tornado developed in Story County and moved into Hamilton County.

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

102°FAug 17, 1988

All-time low

−28°FFeb 2, 1996

Warmest night

79°FJul 10, 1984

Coldest day

−13°FDec 24, 1983

Wettest day

5.59 inAug 22, 1988

Snowiest day

12.0 in2 times, most recently Mar 8, 1998

Hottest year

2024mean 54.0°F

Coldest year

1996mean 46.2°F

Wettest year

199356.35 in

Driest year

198020.82 in

Snowiest season

54.8 in2009-10

Station Ames 8 Wsw (USC00130200), 1,110 ft elevation, 8.7 miles from the population centre. Daily records from 1964 to October 26, 2026; 99.6% 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 USC00130200.
• 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.