Flash Flood Warnings in the United States
133,397 flash flood warnings since 1986. Each alert counts once, however many counties it covered. The archive of flash flood warnings reaches back to 1986.
Flash Flood Warnings by state
Each state shaded by its count. Tap a state for its own archive.
- Flash Flood Warnings
- 133,397
- Busiest year
- 20265,492 flash flood warnings
- Average year
- 3,254over 41 years on file
- Busiest day
- March 1, 1997187 flash flood warnings
Over time
By year
Before October 2007 these were issued for whole counties, and a storm crossing three counties was often three warnings; since then one polygon follows the storm. The count changed with the practice, not only with the weather.
By month of the year
By state
Every state and territory, with the alerts that covered any part of it. Each state’s page lists every one of them.
- Texas19,473
- Arizona7,510
- Missouri6,619
- Arkansas5,311
- Pennsylvania5,205
- Kentucky4,996
- California4,884
- Mississippi4,734
- Virginia4,358
- New Mexico4,305
- North Carolina4,235
- Kansas4,217
- Oklahoma4,107
- Ohio4,104
- Tennessee3,889
- Illinois3,809
- Louisiana3,644
- West Virginia3,453
- Alabama3,428
- New York3,392
- Colorado3,061
- Indiana2,916
- Iowa2,636
- Georgia2,257
- Utah2,134
- Nebraska2,013
- Puerto Rico1,946
- Florida1,712
- Nevada1,685
- Maryland1,567
- New Jersey1,560
- South Carolina1,370
- Minnesota1,247
- Wisconsin1,166
- South Dakota1,089
- Hawaii1,083
- Montana796
- Michigan700
- Idaho664
- Connecticut629
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Sources
National Weather Service watches, warnings, advisories and statements from the Iowa Environmental Mesonet's VTEC archive, which reconstructs tornado, severe thunderstorm, flash flood and marine warnings back to 1986 from the NWS text archive. Storm Prediction Center watches and mesoscale discussions from SPC's archive through the Mesonet. County centers from the US Census Bureau. Rebuilt daily.