Heavy Rain in Grundy County, Iowa

Heavy Rain in Grundy County, Iowa: 50 recorded events between 2009 and 2025. The strongest on record measured 0. That places the county #90 nationally and #24 statewide for this hazard.

Reporting practice changed over time — early decades are undercounted, not calmer.

The busiest decade for heavy rain in Grundy County is the 2010s, when 29 of the county's 50 recorded events were logged. Comparing decades is useful for spotting active periods, but the earliest years are thin because systematic reporting for this hazard began later.

Within the Grundy County archive, heavy rain makes up 14.3% of all recorded severe weather across 8 hazard types. Nationally the county sits at #90 for this hazard and #24 within Iowa, putting it in the 96.3 percentile of all U.S. counties.

Jun is the peak month for heavy rain in Grundy County with 15 recorded events, while Jan is the quietest. Seasonality here is a property of the archive as much as the climate: reports cluster where population and spotter networks are densest.

• Thunderstorm Wind 120
• Hail 91
• Tornado 41

How many heavy rain events are on record in Grundy County, Iowa?

50 heavy rain events are recorded in Grundy County between 2009 and 2025, causing 0 direct deaths.

What is the strongest heavy rain recorded in Grundy County?

The strongest heavy rain on record in Grundy County measured 0.

Where does the heavy rain data for Grundy County come from?

All events come from the NOAA/NCEI Storm Events Database, the federal public-domain archive of severe weather reports. Dates are UTC, damage is as reported and not inflation-adjusted, and the most recent entries may still be revised.