Fog in Toronto, ON

daily fog outlook & 2016–2026 climatology
Fog unlikely through Monday (peak 3%). 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 Billy Bishop Toronto City Airport (CYTZ). Forecast percentages for this station have passed live verification.

Measuring stations

stationairportfog hours/yrforecast
CYTZBilly Bishop Toronto City Airport35 h/yrlive forecast
CYYZToronto Pearson International Airport35 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 Toronto fogs in

Fog here concentrates in November and January — about 35 hours in a typical year at CYTZ, usually lasting ~2 h once it forms. Hour-by-hour patterns, live conditions and the forecast strip live on the CYTZ station page.

Fog season

January: ~5 hJanFebruary: ~2 hFebMarch: ~3 hMarApril: ~3 hAprMay: ~5 hMayJune: ~2 hJunJuly: ~2 hJulAugust: ~1 hAugSeptember: ~1 hSepOctober: ~2 hOctNovember: ~6 hNovDecember: ~2 hDec
Fog season runs October through July, peaking in November; fog is mostly a 4 AM–9 AM phenomenon; typically thinning out by 1 PM; 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.