Fog in Keene, NH

daily fog outlook & 2016–2026 climatology
Some chance of fog — peaks at 41% around 6 am Sunday.forecast cycle 2026-08-16T00:00:00Z · page rebuilt daily · live layers below update hourly

Measured at Dillant Hopkins Airport (KEEN). Forecast percentages for this station have passed live verification.

Measuring station

stationairportfog hours/yrforecast
KEENDillant Hopkins Airport231 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 Keene fogs in

Fog here concentrates in September and October — about 231 hours in a typical year at KEEN, usually lasting ~2 h once it forms. Hour-by-hour patterns, live conditions and the forecast strip live on the KEEN station page.

Fog season

January: ~8 hJanFebruary: ~8 hFebMarch: ~6 hMarApril: ~11 hAprMay: ~14 hMayJune: ~15 hJunJuly: ~21 hJulAugust: ~34 hAugSeptember: ~47 hSepOctober: ~46 hOctNovember: ~12 hNovDecember: ~10 hDec
Fog season runs May through November, peaking in September; fog is mostly a 2 AM–7 AM phenomenon; typically thinning out by 8 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.