Fog in Cheyenne, WY

daily fog outlook & 2016–2026 climatology
Fog possible — NWS guidance shows a fog signal in the next 48 hours. 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 Cheyenne Regional Jerry Olson Field (KCYS). This station is in forecast verification — percentages publish when it clears the accuracy bar.

Measuring station

stationairportfog hours/yrforecast
KCYSCheyenne Regional Jerry Olson Field48 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 Cheyenne fogs in

Fog here concentrates in March and May — about 48 hours in a typical year at KCYS, usually lasting ~1 h once it forms. Hour-by-hour patterns, live conditions and the forecast strip live on the KCYS station page.

Fog season

January: ~3 hJanFebruary: ~4 hFebMarch: ~8 hMarApril: ~6 hAprMay: ~8 hMayJune: ~1 hJunJuly: ~1 hJulAugust: ~2 hAugSeptember: ~2 hSepOctober: ~4 hOctNovember: ~5 hNovDecember: ~4 hDec
Fog season runs August through May, peaking in March; fog is mostly a 2 AM–8 AM phenomenon; typically thinning out by 1 PM; 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.