Fog in St. John's, NL

daily fog outlook & 2016–2026 climatology
Forecast feed initializing for this station. August typically brings about 19 hours of dense fog here (10-year average).

Measured at St. John's International Airport (CYYT). This station is in forecast verification — percentages publish when it clears the accuracy bar.

Measuring station

stationairportfog hours/yrforecast
CYYTSt. John's International Airport535 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 St. John's fogs in

Fog here concentrates in May and April — about 535 hours in a typical year at CYYT, usually lasting ~2 h once it forms. Hour-by-hour patterns, live conditions and the forecast strip live on the CYYT station page.

Fog season

January: ~32 hJanFebruary: ~26 hFebMarch: ~37 hMarApril: ~70 hAprMay: ~80 hMayJune: ~70 hJunJuly: ~44 hJulAugust: ~19 hAugSeptember: ~33 hSepOctober: ~35 hOctNovember: ~51 hNovDecember: ~34 hDec
Fog season runs September through July, peaking in May; fog here can hit at any hour of the day; 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.