EFHK — Helsinki Vantaa Airport

fog forecast & climatology · Helsinki (Vantaa) city page · full 10-year analysis →
No fog forecast feed exists for this station. September typically brings about 16 hours of dense fog here (10-year average).

Fog hours per year
134 h below CAT I minima (2016–2026 average)
Fog season
February and January
Typical fog event
~2 h once it forms (middle half 1–4 h, n=510)
Data through
2026-08-15 · machine-readable data.json

When this airport fogs in

In a typical year Helsinki Vantaa Airport spends 134 hours below CAT I approach minima (visibility under ~½ mile or ceiling under 200 ft), concentrated in February and January. The strip above shows the hour-by-hour pattern for the current month from ten years of weather observations.

Fog season

January: ~20 hJanFebruary: ~20 hFebMarch: ~20 hMarApril: ~10 hAprMay: ~4 hMayJune: ~1 hJunJuly: ~3 hJulAugust: ~5 hAugSeptember: ~16 hSepOctober: ~8 hOctNovember: ~10 hNovDecember: ~17 hDec
Fog season runs August through April, peaking in January; fog is mostly a 1 AM–10 AM phenomenon; 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.