Fog in Washington, DC

daily fog outlook & 2016–2026 climatology
No fog signal in NWS guidance for the next 48 hours. dense fog (visibility under a mile) is rare here in August.forecast cycle 2026-08-16T00:00:00Z · page rebuilt daily · live layers below update hourly

Measured at Ronald Reagan Washington National Airport (KDCA). This station is in forecast verification — percentages publish when it clears the accuracy bar.

Measuring station

stationairportfog hours/yrforecast
KDCARonald Reagan Washington National Airport13 h/yrverifying

Fog is measured where instruments live — airports. Hours/yr = time below CAT I approach minima (visibility under ~½ mile or ceiling under 200 ft), the aviation definition of seriously dense fog.

When Washington fogs in

Fog here concentrates in January and December — about 13 hours in a typical year at KDCA, usually lasting ~1 h once it forms. Hour-by-hour patterns, live conditions and the forecast strip live on the KDCA station page.

Fog season

January: ~3 hJanFebruary: ~2 hFebMarch: ~1 hMarApril: ~0 hAprMay: ~1 hMayJune: ~0 hJunJuly: ~0 hJulAugust: ~0 hAugSeptember: ~0 hSepOctober: ~1 hOctNovember: ~1 hNovDecember: ~3 hDec
Fog season runs December through February, peaking in January; fog is mostly a midnight–3 AM phenomenon; typically thinning out by 10 AM; a typical event lasts about 1 hour once it forms local time · 10-yr average

Machine access: data.json · llms.txt · forecast verification. Not for operational use.