Fog in Sidney, MT

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 Sidney - Richland Regional Airport (KSDY). This station is in forecast verification — percentages publish when it clears the accuracy bar.

Measuring station

stationairportfog hours/yrforecast
KSDYSidney - Richland Regional Airport25 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 Sidney fogs in

Fog here concentrates in November and January — about 25 hours in a typical year at KSDY, usually lasting ~1 h once it forms. Hour-by-hour patterns, live conditions and the forecast strip live on the KSDY station page.

Fog season

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