LSMA — Alpnach Air Base

fog forecast & climatology · Alpnach city page · full 10-year analysis →
No fog forecast feed exists for this station. September typically brings about 1 hour of dense fog here (10-year average).

Fog hours per year
91 h below CAT I minima (2016–2026 average)
Fog season
December and November
Typical fog event
~2 h once it forms (middle half 1–3 h, n=364)
Data through
2026-08-15 · machine-readable data.json

When this airport fogs in

In a typical year Alpnach Air Base spends 91 hours below CAT I approach minima (visibility under ~½ mile or ceiling under 200 ft), concentrated in December and November. The strip above shows the hour-by-hour pattern for the current month from ten years of weather observations.

Fog season

January: ~19 hJanFebruary: ~8 hFebMarch: ~4 hMarApril: ~2 hAprMay: ~1 hMayJune: ~0 hJunJuly: ~0 hJulAugust: ~1 hAugSeptember: ~1 hSepOctober: ~9 hOctNovember: ~18 hNovDecember: ~30 hDec
Fog season runs October through February, peaking in December; fog is mostly a 3 AM–10 AM phenomenon; typically thinning out by noon; 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.