Fremont County

Every recorded tornado

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

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. Mar 13, 2019Flood$22.0 million
   National Weather Service narrative

   Flooding along the Nishnabotna River. The river gage above Hamburg, operated by the USGS, peaked at 31.07 feet at 11 am on March 16th. Moderate flood stage is 27.5 feet while major flood stage is 33 feet. Preliminary informations shows this peak is the 3rd highest on record. Flooding also occurred along the Missouri River. The river gage at Nebraska City, operated by the USGS, peaked at 30.15 feet at 6 pm on March 16th. Minor flood stage is 18 feet, moderate flood stage is 23 feet while major flood stage is 27 feet. Preliminary data shows this to be a record crest. Flooding continued into the next month. Levees 601, 594 and 575 failed flooding Bartlett, Percival, Hamburg, and the…

2. Mar 17, 2019Flash Flood$14.0 million
   National Weather Service narrative

   Thurman was evacuated due to a levee break on the Missouri River.

3. Aug 1, 2011Flood$10.0 million
   National Weather Service narrative

   Flooding along the Missouri River gradually worsened over the area during June into July as record inflows into the Missouri River above Sioux City in June and much above normal inflows during July prompted record releases from Gavins Point Dam. The river at Nebraska City reached a record crest of a little over 28 feet by the end of the June before falling through early July as levees in the area were breached and widened by flood waters. Although moderate flooding still persisted into August, river values started falling by the end of the month and minor flooding continued into September as outflows from Gavins Point were reduced. River values at Nebraska City started August a…

4. Sep 1, 2011Flood$3.0 million
   National Weather Service narrative

   Flooding along the Missouri River gradually improved over the area during September as releases from Gavins Point Dam were reduced. The river at Nebraska City, which reached a record crest of a little over 28 feet by the end of the June, had fallen to around 20.5 feet by the first of September and finally below its 18 foot flood stage during the evening of Sept. 28th. However, extensive flooding of farm fields, roads and highways that had occurred over the summer as levees near Hamburg and Percival failed persisted into September. The flooding caused the closure of 24 miles of Interstate 29 and Highway 2 into Nebraska City as well as other local roads and highways. After the flood…

5. Oct 25, 1997Heavy Snow, Fremont$900,000
   National Weather Service narrative

   A major early season snowstorm struck portions of southwestern Iowa, blanketing the area with 6 to 9 inches of heavy wet snow. The snow fell on trees, many of which were still fully or partially leafed, and caused extensive damage and/or total destruction. Thousands of residents were without power just after the storm and many of the outages lasted for several days. Emergency shelters were opened in the affected areas for use by those who suffered a hardship from the storm.

6. May 6, 2007Flood$500,000
   National Weather Service narrative

   Heavy rainfall over the weekend of May 4th through the 6th, caused the Nishnabotna River to flood across Fremont county. The Nishnabotna River at Hamburg reached a prolonged crest of around 32.4 feet between 715 pm and 1145 pm on May 8th. Flood stage is 23 feet. The river at Hamburg first crossed flood stage around 6 am CDT on May 6th and didn't drop below flood stage until around 7 am on May 15th.|The flooding closed Interstate 29 for a while and an agricultural levee broke south of town sending significant amounts of water across agricultural bottom lands and county roads in the region early May 7th.|Flooding was also observed along the East Nishnabotna River northeast of…

7. Jun 1, 2011Flood$500,000
   National Weather Service narrative

   Flooding along the Missouri River gradually worsened over the area during June as record releases from Gavins Point Dam and periodic heavy rain brought widespread flooding along the River. The river at Nebraska City, which climbed above its 18 foot flood stage in mid April, started June around 23 feet and then began rising by the 10th eventually reaching a record crest a little over 28 feet by the end of the month. The river stayed well above flood stage into July. A levee west and southwest of Hamburg experienced seepage in several areas prompting partial evacuation of Hamburg on the 5th. The levee eventually failed by the middle of June causing extensive flooding of farmland,…

8. Jul 1, 2011Flood$150,000
   National Weather Service narrative

   Flooding along the Missouri River gradually worsened over the area during June as record releases from Gavins Point Dam and periodic heavy rain brought widespread flooding along the River. The river at Nebraska City reached a record crest a little over 28 feet by the end of the June before falling through early July as levees in the area were breached and widened by flood waters. However, significant flooding persisted through much of July and August. A levee west and southwest of Hamburg failed by the middle of June causing extensive flooding of farmland, roads and a few roads or highways near Hamburg, including 10 miles of Interstate 29. By mid July around 24 miles of Interstate…

9. Jun 13, 2011Flash Flood$100,000
   National Weather Service narrative

   A federal levee along the Missouri River failed causing flash flooding of several farmsteads southwest of Hamburg. The flood waters also flooded across a local highway and eventually reached Interstate 29 and a levee surrounding Hamburg.

10. Jun 5, 2008Lightning$100,000
    National Weather Service narrative

    Lightning apparently struck a house causing a fire that totally destroyed it.

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

113°FAug 4, 1918

All-time low

−29°FFeb 5, 1936

Warmest night

87°FJul 25, 1936

Coldest day

−12°FDec 22, 1989

Wettest day

5.89 inSep 8, 1989

Snowiest day

18.0 inFeb 21, 1945

Hottest year

2012mean 55.4°F

Coldest year

1996mean 48.6°F

Wettest year

199351.46 in

Driest year

195619.79 in

Snowiest season

56.0 in2009-10

Station Shenandoah (USC00137613), 969 ft elevation, 12.8 miles from the population centre. Daily records from 1918 to October 27, 2026; 99.1% 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 USC00137613.
• 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.