Fog in Harrisburg, PA

daily fog outlook & 2016–2026 climatology
No fog signal in NWS guidance for the next 48 hours. August typically brings about 1 hour of dense fog here.forecast cycle 2026-08-16T00:00:00Z · page rebuilt daily · live layers below update hourly

Measured at Harrisburg International Airport (KMDT). This station is in forecast verification — percentages publish when it clears the accuracy bar.

Measuring station

stationairportfog hours/yrforecast
KMDTHarrisburg International Airport59 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 Harrisburg fogs in

Fog here concentrates in December and January — about 59 hours in a typical year at KMDT, usually lasting ~2 h once it forms. Hour-by-hour patterns, live conditions and the forecast strip live on the KMDT station page.

Fog season

January: ~11 hJanFebruary: ~10 hFebMarch: ~8 hMarApril: ~1 hAprMay: ~3 hMayJune: ~1 hJunJuly: ~0 hJulAugust: ~1 hAugSeptember: ~2 hSepOctober: ~3 hOctNovember: ~3 hNovDecember: ~15 hDec
Fog season runs December through March, peaking in December; fog here can hit at any hour of the day; 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.