Alert archive / Dense Fog Advisories / 2021
Dense Fog Advisories in the United States, December 2021
390 dense fog advisories in December 2021. 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
- 390
- Busiest day
- December 31, 202138 dense fog advisories
Over time
By day
Days in UTC, the clock the archive keeps.
By state
Every state and territory, with the alerts that covered any part of it. Each state’s page lists every one of them.
- Texas225
- Florida168
- California141
- Georgia123
- Mississippi110
- Alabama95
- Louisiana94
- Kansas85
- Minnesota82
- Missouri76
- Illinois75
- Nebraska73
- North Carolina67
- Wisconsin67
- South Carolina66
- Iowa65
- Arkansas57
- Tennessee57
- Indiana55
- Alaska45
- Virginia44
- South Dakota40
- Oregon38
- Kentucky38
- Oklahoma36
- Maine35
- Ohio30
- Colorado30
- Michigan28
- North Dakota27
- Pennsylvania22
- Wyoming21
- Montana20
- Washington20
- West Virginia20
- Maryland19
- Idaho17
- New Mexico14
- Massachusetts13
- New York11
Nearby
Alerts in force nowThe tornado archiveThe radar archive20202022
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.