Fog in Rapid City, SD

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 Rapid City Regional Airport (KRAP). Forecast percentages for this station have passed live verification.

Measuring stations

stationairportfog hours/yrforecast
KRAPRapid City Regional Airport63 h/yrlive forecast
KRCAEllsworth Air Force Base102 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 Rapid City fogs in

Fog here concentrates in March and January — about 63 hours in a typical year at KRAP, usually lasting ~1 h once it forms. Hour-by-hour patterns, live conditions and the forecast strip live on the KRAP station page.

Fog season

January: ~11 hJanFebruary: ~7 hFebMarch: ~11 hMarApril: ~4 hAprMay: ~4 hMayJune: ~1 hJunJuly: ~3 hJulAugust: ~3 hAugSeptember: ~3 hSepOctober: ~6 hOctNovember: ~3 hNovDecember: ~8 hDec
Fog season runs July through May, peaking in January; fog is mostly a 2 AM–9 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.