Fog in Watertown, SD

daily fog outlook & 2016–2026 climatology
No fog signal in NWS guidance for the next 48 hours. August typically brings about 6 hours of dense fog here.forecast cycle 2026-08-16T00:00:00Z · page rebuilt daily · live layers below update hourly

Measured at Watertown Regional Airport (KATY). This station is in forecast verification — percentages publish when it clears the accuracy bar.

Measuring station

stationairportfog hours/yrforecast
KATYWatertown Regional Airport82 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 Watertown fogs in

Fog here concentrates in January and December — about 82 hours in a typical year at KATY, usually lasting ~1 h once it forms. Hour-by-hour patterns, live conditions and the forecast strip live on the KATY station page.

Fog season

January: ~16 hJanFebruary: ~9 hFebMarch: ~11 hMarApril: ~9 hAprMay: ~3 hMayJune: ~1 hJunJuly: ~2 hJulAugust: ~6 hAugSeptember: ~4 hSepOctober: ~3 hOctNovember: ~6 hNovDecember: ~13 hDec
Fog season is January, February, March, April, August, September, November, December, peaking in January; fog is mostly a 1 AM–10 AM phenomenon; typically thinning out by 11 AM; 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.