Fog in La Grande-4, QC

daily fog outlook & 2016–2026 climatology
Fog unlikely through Monday (peak 9%). August typically brings about 4 hours of dense fog here.forecast cycle 2026-08-16T00:00:00Z · page rebuilt daily · live layers below update hourly

Measured at La Grande-4 Airport (CYAH). Forecast percentages for this station have passed live verification.

Measuring station

stationairportfog hours/yrforecast
CYAHLa Grande-4 Airport34 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 La Grande-4 fogs in

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

Fog season

January: ~1 hJanFebruary: ~2 hFebMarch: ~2 hMarApril: ~1 hAprMay: ~2 hMayJune: ~4 hJunJuly: ~7 hJulAugust: ~4 hAugSeptember: ~4 hSepOctober: ~3 hOctNovember: ~1 hNovDecember: ~3 hDec
Fog season is February, March, May, June, July, August, September, October, December, peaking in July; fog is mostly a 4 AM–7 AM phenomenon; typically thinning out by 10 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.