Dense Fog Advisories in the United States
30,101 dense fog advisories since 1986. Each alert counts once, however many counties it covered. The archive of dense fog advisories reaches back to 2005.
Dense Fog Advisories by state
Each state shaded by its count. Tap a state for its own archive.
- Dense Fog Advisories
- 30,101
- Busiest year
- 20241,963 dense fog advisories
- Average year
- 1,368over 22 years on file
- Busiest day
- January 24, 202456 dense fog advisories
Over time
By year
Before late 2005 the archive holds only tornado, severe thunderstorm, flash flood and marine warnings, and from 1997 SPC's watches, so the jump that year is the archive widening, not 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.
- Texas3,752
- Florida2,446
- California2,195
- Kansas1,856
- Georgia1,785
- Alabama1,571
- Mississippi1,563
- Minnesota1,466
- Louisiana1,463
- Missouri1,422
- Illinois1,407
- Iowa1,327
- Wisconsin1,322
- Alaska1,293
- North Carolina1,262
- Nebraska1,247
- South Carolina1,096
- Arkansas1,014
- Oregon984
- Indiana955
- Tennessee874
- Virginia750
- Oklahoma744
- Kentucky711
- South Dakota697
- Michigan682
- Washington663
- North Dakota652
- Colorado648
- Ohio630
- Pennsylvania593
- Maryland570
- Montana559
- Maine530
- Idaho472
- New York432
- Wyoming414
- West Virginia376
- Massachusetts362
- Connecticut345
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.