Fog in Waterloo, IA

daily fog outlook & 2016–2026 climatology
No fog signal in NWS guidance for the next 48 hours. August typically brings about 4 hours of dense fog here.forecast cycle 2026-08-16T00:00:00Z · page rebuilt daily · live layers below update hourly

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

Measuring station

stationairportfog hours/yrforecast
KALOWaterloo Regional Airport48 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 Waterloo fogs in

Fog here concentrates in January and February — about 48 hours in a typical year at KALO, usually lasting ~2 h once it forms. Hour-by-hour patterns, live conditions and the forecast strip live on the KALO station page.

Fog season

January: ~8 hJanFebruary: ~7 hFebMarch: ~4 hMarApril: ~1 hAprMay: ~4 hMayJune: ~1 hJunJuly: ~1 hJulAugust: ~4 hAugSeptember: ~3 hSepOctober: ~3 hOctNovember: ~4 hNovDecember: ~7 hDec
Fog season is January, February, March, May, August, September, October, November, December, peaking in January; fog is mostly a 1 AM–8 AM phenomenon; typically thinning out by 10 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.