Greene County

Every recorded tornado

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

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.

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.

Costliest events since 1996

1. Aug 1, 2003Drought, Greene$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. Dec 15, 2021Tornado$1.2 million
   National Weather Service narrative

   This tornado occurred southwest of Jefferson and remained in rural Greene County during its entire path. The tornado damaged a confinement building and farther northeast destroyed an outbuilding. However, the most intense damage was a series of high voltage utility dual pole towers which were snapped by the tornado. At least 8 towers were snapped over J Avenue between 250th and 260th Streets. Additional utility poles were snapped along 250th Street as well. The tornado lifted in the vicinity of an apple orchard located southwest of Jefferson.

3. Dec 23, 2009Ice Storm, Greene$1.0 million
   National Weather Service narrative

   Part 1 of 2: A major winter storm system affected the central U.S. during Christmas week. There were two upper level systems involved with this storm. The southern stream low dove into the southern U.S. and then turned northeast. The turn was sharper than is typical as the northern stream upper low pushed southeast. The southern stream and polar low interacted with each other, resulting in a Fuji Wara effect. The southern low turned north, then eventually northwest and moved from northern Louisiana into Iowa. This resulted in a considerable amount of warm air being drawn north over Iowa. Cold air remained in place at the surface due to an existing deep snow cover over most of the…

4. Dec 15, 2021Tornado$800,000
   National Weather Service narrative

   Tornado moved into Greene County from Guthrie County. This tornado produced damage through rural south and east portions of the county. The tornado passed just southeast of the hamlet of Cooper and through Grand Junction. Most of the damage was EF0 to EF1 with tree and minor house damage. However, the tornado strengthened north of Grand Junction with power pole damage and then toppling an industrial wind mill along W Avenue with an EF2 rating at that location. The circulation then destroyed a confinement building before dissipating several miles northeast of Dana.

5. Dec 15, 2021Tornado$500,000
   National Weather Service narrative

   Another QLCS tornado which began west southwest of Jefferson and ended to the northwest of town. This tornado began in rural areas but toppled several large single pole utility poles along I Avenue south of 250th Street and moved northeast with tree and minor house damage on 240th Street near the intersection with K Avenue. The tornado ended up crossing US Highway 30 about 1.5 miles west of the intersection with State Highway 4 and severely leaned high voltage poles along the highway. The tornado dissipated not long afterwards near M Avenue north of Highway 30.

6. Dec 15, 2021Tornado$350,000
   National Weather Service narrative

   Tornado continued into Greene County from Guthrie County. The path through Greene County was long but remained in rural portions of the county. Damage to rural outbuildings occurred in southern Greene county with more intense damage south of Jefferson. Utility poles were snapped along 280th Street near where N Avenue intersects the road. The tornado then impacted a farmstead on the west side of Highway 4 destroying several outbuildings and producing minor damage to the home. The tornado proceeded northeast crossing US Highway 30 east of Jefferson and then continued in rural areas before lifting north of Dana.

7. Nov 10, 1998High Wind, Greene$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…

8. Apr 25, 2007Flood$250,000
   National Weather Service narrative

   A strong low pressure developed over eastern Colorado and moved southeast into northern Oklahoma by the 24th. Deep moisture was pulled north ahead of the low with surface dew points in the low 70s reaching northern Oklahoma. Strong isentropic lift took place over the Des Moines CWA and resulted in a large and sustained area of rain and embedded thunderstorms. Rainfall of two to over five inches of rainfall occurred over a large part of the CWA, with isolated amounts in the six to seven inch range over a 2 day period. This event brought about the flash flooding event of the evening of the 24th. The situation transitioned into a general areal flood event on the 25th, with several…

9. Apr 24, 2007Flood$250,000
   National Weather Service narrative

   There were two periods of noteworthy precipitation during the month. Snow fell nearly statewide on the 10th and 11th with up to 10.5 inches in Dickinson County while an inch or more accumulated over about the northeastern two-thirds of the state. The other event was a period of prolonged rainfall from the 22nd through the 26th. An average of 2.82 inches of rain fell across the state during this five day period. Only a small area of far northwest Iowa failed to receive at least an inch or rain while Guthrie Center reported the most with 7.28 inches. Heaviest rains were centered across central and west central Iowa with minor to moderate flooding resulting in these areas and points…

10. Feb 24, 2007Winter Storm, Greene$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…

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

111°FJul 5, 1911

All-time low

−37°FJan 12, 1912

Warmest night

92°FAug 4, 1930

Coldest day

−14°FJan 12, 1912

Wettest day

7.83 inJul 9, 1993

Snowiest day

14.0 inJan 1, 1942

Hottest year

1987mean 53.4°F

Coldest year

1917mean 44.9°F

Wettest year

190249.97 in

Driest year

193020.18 in

Snowiest season

68.8 in1961-62

Station Jefferson (USC00134228), 1,055 ft elevation, 1.5 miles from the population centre. Daily records from 1893 to September 18, 2026; 86.7% 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 USC00134228.
• 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.