Grundy County

Every recorded tornado

1. Injuries and deaths are for the tornado’s whole path, which may extend beyond the county. Deaths recorded within Grundy 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. Apr 10, 1997Heavy Snow, Grundy$3.0 million
   National Weather Service narrative

   Heavy wet snow fell across the Northern third of Missouri throughout the day on the 10th followed by a second band of snow during the early morning hours of the 11th. Since temperatures were near or slightly over freezing during the snowfall, some of the snow melted quickly but 6 to 12 inches of snow accumulated with well over a foot in many locations. The heaviest snow fell along and to the north of Highway 136 from Albany in Gentry County to Prineton in Mercer County to Lancaster in Schuyler County. The greatest totals were recorded in Schuyler and Mercer Counties where 20-24 inches of snow was reported. Schuyler County Emergency Management reported 24 inches of snow at…

2. May 27, 2004Hail$300,000
   National Weather Service narrative

   There was extensive damage to roofs and cars. Power lines were also reported down.

3. Jun 6, 1999Thunderstorm Wind$15,000
   National Weather Service narrative

   Power lines and poles were downed by thunderstorm winds.

4. Jun 12, 2004Thunderstorm Wind$10,000
5. Aug 28, 2018Thunderstorm Wind$10,000
   National Weather Service narrative

   A few large trees were blown down and a shed was blown in just west of Galt.

6. Nov 11, 2015Thunderstorm Wind$5,000
   National Weather Service narrative

   A large portion of a shingled roof was blown off along Route W.

7. Dec 10, 2007Ice Storm, Grundy$5,000
   National Weather Service narrative

   One quarter to one half inch of ice was reported across the county. Many tree branches and power lines were reported down.

8. May 12, 2010Thunderstorm Wind$5,000
   National Weather Service narrative

   Two foot diamater tree limbs fell on to a house. A three foot diameter tree was snapped off in the downtown area.

9. Jul 3, 2001Thunderstorm Wind$3,000
   National Weather Service narrative

   Ham radio reported 3/4 inch hail and wind gusts to 80 mph. Trees up to 2 feet in diameter blown down.

10. Jun 26, 2011Thunderstorm Wind$3,000
    National Weather Service narrative

    Thunderstorm wind gusts were estimated up to 80 mph. Power lines were snapped and an outbuilding was destroyed.

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

114°FJul 15, 1936

All-time low

−26°FJan 22, 1930

Warmest night

90°F2 times, most recently Jul 3, 1911

Coldest day

−7°F3 times, most recently Jan 15, 2024

Wettest day

6.66 inSep 7, 1914

Snowiest day

12.0 inMar 30, 1899

Hottest year

1938mean 57.1°F

Coldest year

1978mean 48.8°F

Wettest year

200859.03 in

Driest year

193622.98 in

Snowiest season

51.2 in1978-79

Station Trenton (USC00238444), 837 ft elevation, 1.0 miles from the population centre. Daily records from 1895 to October 27, 2026; 93.4% 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 USC00238444.
• 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.