Fog in Trois-Rivières, QC

daily fog outlook & 2016–2026 climatology
No fog signal in NWS guidance for the next 48 hours. August typically brings about 3 hours of dense fog here.forecast cycle 2026-08-16T00:00:00Z · page rebuilt daily · live layers below update hourly

Measured at Trois-Rivières Airport (CYRQ). This station is in forecast verification — percentages publish when it clears the accuracy bar.

Measuring station

stationairportfog hours/yrforecast
CYRQTrois-Rivières Airport75 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 Trois-Rivières fogs in

Fog here concentrates in December and October — about 75 hours in a typical year at CYRQ, usually lasting ~2 h once it forms. Hour-by-hour patterns, live conditions and the forecast strip live on the CYRQ station page.

Fog season

January: ~6 hJanFebruary: ~6 hFebMarch: ~8 hMarApril: ~7 hAprMay: ~2 hMayJune: ~3 hJunJuly: ~2 hJulAugust: ~3 hAugSeptember: ~8 hSepOctober: ~10 hOctNovember: ~8 hNovDecember: ~13 hDec
Fog season runs September through April, peaking in December; fog is mostly a 3 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.