Fog in Helsinki (Vantaa)

daily fog outlook & 2016–2026 climatology
No fog forecast feed exists for this station. August typically brings about 5 hours of dense fog here (10-year average).

Measured at Helsinki Vantaa Airport (EFHK). This station has climatology and live observations only.

Measuring station

stationairportfog hours/yrforecast
EFHKHelsinki Vantaa Airport134 h/yrclimatology

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 Helsinki (Vantaa) fogs in

Fog here concentrates in February and January — about 134 hours in a typical year at EFHK, usually lasting ~2 h once it forms. Hour-by-hour patterns, live conditions and the forecast strip live on the EFHK station page.

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

Machine access: data.json · llms.txt · forecast verification. Not for operational use.