Fog in Green Bay, WI

daily fog outlook & 2016–2026 climatology
Fog unlikely through Sunday (peak 5%). August typically brings about 3 hours of dense fog here.forecast cycle 2026-08-16T00:00:00Z · page rebuilt daily · live layers below update hourly

Measured at Austin Straubel International Airport (KGRB). Forecast percentages for this station have passed live verification.

Measuring station

stationairportfog hours/yrforecast
KGRBAustin Straubel International Airport55 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 Green Bay fogs in

Fog here concentrates in January and December — about 55 hours in a typical year at KGRB, usually lasting ~2 h once it forms. Hour-by-hour patterns, live conditions and the forecast strip live on the KGRB station page.

Fog season

January: ~10 hJanFebruary: ~7 hFebMarch: ~4 hMarApril: ~6 hAprMay: ~3 hMayJune: ~0 hJunJuly: ~2 hJulAugust: ~3 hAugSeptember: ~8 hSepOctober: ~2 hOctNovember: ~3 hNovDecember: ~9 hDec
Fog season is January, February, March, April, May, August, September, November, December, peaking in January; fog is mostly a 1 AM–8 AM phenomenon; typically thinning out by 11 AM; 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.