Fog in London, ON

daily fog outlook & 2016–2026 climatology
Fog unlikely through Monday (peak 9%). 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 London International Airport (CYXU). Forecast percentages for this station have passed live verification.

Measuring station

stationairportfog hours/yrforecast
CYXULondon International Airport90 h/yrlive forecast

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 London fogs in

Fog here concentrates in December and January — about 90 hours in a typical year at CYXU, usually lasting ~2 h once it forms. Hour-by-hour patterns, live conditions and the forecast strip live on the CYXU station page.

Fog season

January: ~14 hJanFebruary: ~10 hFebMarch: ~10 hMarApril: ~5 hAprMay: ~5 hMayJune: ~2 hJunJuly: ~3 hJulAugust: ~6 hAugSeptember: ~7 hSepOctober: ~6 hOctNovember: ~6 hNovDecember: ~17 hDec
Fog season runs August through May, peaking in December; fog is mostly a 2 AM–9 AM phenomenon; typically thinning out by noon; 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.