UMBB — Brest International Airport

fog forecast & climatology · full 10-year analysis →
No fog forecast feed exists for this station. September typically brings about 47 hours of dense fog here (10-year average).

Fog hours per year
169 h below CAT I minima (2016–2026 average)
Fog season
December and September
Typical fog event
~2 h once it forms (middle half 1–3 h, n=341)
Data through
2026-08-15 · machine-readable data.json

When this airport fogs in

In a typical year Brest International Airport spends 169 hours below CAT I approach minima (visibility under ~½ mile or ceiling under 200 ft), concentrated in December and September. The strip above shows the hour-by-hour pattern for the current month from ten years of weather observations.

Fog season

January: ~16 hJanFebruary: ~13 hFebMarch: ~4 hMarApril: ~9 hAprMay: ~3 hMayJune: ~8 hJunJuly: ~3 hJulAugust: ~5 hAugSeptember: ~47 hSepOctober: ~24 hOctNovember: ~21 hNovDecember: ~57 hDec
Fog season runs September through January, peaking in December; fog is mostly a 3 AM–3 AM phenomenon; typically thinning out by 9 AM; a typical event lasts about 2 hours 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.