Fog in Appleton, WI

daily fog outlook & 2016–2026 climatology
Fog unlikely through Sunday (peak 7%). August typically brings about 2 hours of dense fog here.forecast cycle 2026-08-16T00:00:00Z · page rebuilt daily · live layers below update hourly

Measured at Appleton International Airport (KATW). Forecast percentages for this station have passed live verification.

Measuring station

stationairportfog hours/yrforecast
KATWAppleton International Airport54 h/yrlive forecast

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 Appleton fogs in

Fog here concentrates in December and February — about 54 hours in a typical year at KATW, usually lasting ~2 h once it forms. Hour-by-hour patterns, live conditions and the forecast strip live on the KATW station page.

Fog season

January: ~10 hJanFebruary: ~12 hFebMarch: ~5 hMarApril: ~6 hAprMay: ~4 hMayJune: ~1 hJunJuly: ~0 hJulAugust: ~2 hAugSeptember: ~3 hSepOctober: ~1 hOctNovember: ~1 hNovDecember: ~14 hDec
Fog season runs December through May, peaking in December; fog is mostly a 11 PM–10 AM phenomenon; typically thinning out by 1 PM; a typical event lasts about 2 hours once it forms local time · 10-yr average

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