Fog in Unalaska, AK

daily fog outlook & 2016–2026 climatology
Fog possible — NWS guidance shows a fog signal in the next 48 hours. August typically brings about 11 hours of dense fog here.forecast cycle 2026-08-16T00:00:00Z · page rebuilt daily · live layers below update hourly

Measured at Tom Madsen (Dutch Harbor) Airport (PADU). This station is in forecast verification — percentages publish when it clears the accuracy bar.

Measuring station

stationairportfog hours/yrforecast
PADUTom Madsen (Dutch Harbor) Airport38 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 Unalaska fogs in

Fog here concentrates in August and July — about 38 hours in a typical year at PADU, usually lasting ~1 h once it forms. Hour-by-hour patterns, live conditions and the forecast strip live on the PADU station page.

Fog season

January: ~1 hJanFebruary: ~1 hFebMarch: ~1 hMarApril: ~1 hAprMay: ~0 hMayJune: ~8 hJunJuly: ~11 hJulAugust: ~11 hAugSeptember: ~1 hSepOctober: ~0 hOctNovember: ~1 hNovDecember: ~0 hDec
Fog season runs June through August, peaking in July; fog is mostly a 3 AM–noon phenomenon; typically thinning out by 3 PM; 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.