CYFS — Fort Simpson Airport

fog forecast & climatology · Fort Simpson city page · full 10-year analysis →
Fog unlikely through Friday (peak 3%). September typically brings about 7 hours of dense fog here.forecast cycle 2026-09-04T13:00:00Z · page rebuilt daily · live layers below update hourly

Fog hours per year
42 h below CAT I minima (2016–2026 average)
Fog season
October and September
Typical fog event
~1 h once it forms (middle half 1–2 h, n=206)
Data through
2026-08-15 · machine-readable data.json

When this airport fogs in

In a typical year Fort Simpson Airport spends 42 hours below CAT I approach minima (visibility under ~½ mile or ceiling under 200 ft), concentrated in October and September. The strip above shows the hour-by-hour pattern for the current month from ten years of weather observations.

Fog season

January: ~1 hJanFebruary: ~1 hFebMarch: ~1 hMarApril: ~2 hAprMay: ~0 hMayJune: ~0 hJunJuly: ~5 hJulAugust: ~4 hAugSeptember: ~7 hSepOctober: ~15 hOctNovember: ~4 hNovDecember: ~3 hDec
Fog season runs July through November, peaking in October; fog is mostly a 4 AM–10 AM phenomenon; typically thinning out by 1 PM; a typical event lasts about 1 hour once it forms local time · 10-yr average

For flight operations

EFVS crews: the CHASE board ranks airports by live fog status, approach lighting, go-around height and flight time from your base. Forecast probabilities publish here per-airport once the calibrated model beats climatology on live verification — receipts on the scorecard. Methodology.

Sources: NOAA/NWS National Blend of Models guidance · METAR observations 2016–2026 (Iowa Environmental Mesonet) · FAA NASR. Machine access: data.json · llms.txt. Not for operational use.