Fog in San Diego, CA

daily fog outlook & 2016–2026 climatology
No fog signal in NWS guidance for the next 48 hours. August typically brings about 1 hour of dense fog here.forecast cycle 2026-08-16T00:00:00Z · page rebuilt daily · live layers below update hourly

Measured at San Diego International Airport (KSAN). This station is in forecast verification — percentages publish when it clears the accuracy bar.

Measuring stations

stationairportfog hours/yrforecast
KSANSan Diego International Airport34 h/yrverifying
KSDMBrown Field Municipal Airport119 h/yrverifying
KNKXMiramar Marine Corps Air Station - Mitscher Field88 h/yrverifying
KNZYNorth Island Naval Air Station-Halsey Field74 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 San Diego fogs in

Fog here concentrates in December and October — about 34 hours in a typical year at KSAN, usually lasting ~1 h once it forms. Hour-by-hour patterns, live conditions and the forecast strip live on the KSAN station page.

Fog season

January: ~5 hJanFebruary: ~5 hFebMarch: ~2 hMarApril: ~2 hAprMay: ~0 hMayJune: ~0 hJunJuly: ~0 hJulAugust: ~1 hAugSeptember: ~1 hSepOctober: ~7 hOctNovember: ~6 hNovDecember: ~8 hDec
Fog season runs October through April, peaking in December; fog is mostly a 11 PM–6 AM phenomenon; typically thinning out by 8 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.