Fog in Modesto, CA

daily fog outlook & 2016–2026 climatology
No fog signal in NWS guidance for the next 48 hours. dense fog (visibility under a mile) is rare here in August.forecast cycle 2026-08-16T00:00:00Z · page rebuilt daily · live layers below update hourly

Measured at Modesto City Co-Harry Sham Field (KMOD). This station is in forecast verification — percentages publish when it clears the accuracy bar.

Measuring station

stationairportfog hours/yrforecast
KMODModesto City Co-Harry Sham Field94 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 Modesto fogs in

Fog here concentrates in January and December — about 94 hours in a typical year at KMOD, usually lasting ~2 h once it forms. Hour-by-hour patterns, live conditions and the forecast strip live on the KMOD station page.

Fog season

January: ~41 hJanFebruary: ~8 hFebMarch: ~1 hMarApril: ~0 hAprMay: ~0 hMayJune: ~0 hJunJuly: ~0 hJulAugust: ~0 hAugSeptember: ~0 hSepOctober: ~0 hOctNovember: ~12 hNovDecember: ~32 hDec
Fog season runs November through January, peaking in January; fog is mostly a 3 AM–9 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.