How humid is Finland in 2026?

FMI climate guidance puts mean relative humidity near 90% in November and December, and near 65% to 70% in May and June. That winter spike is why a 0°C Helsinki day can feel clammy indoors when wet coats dry in a closed flat: Living in Helsinki and Winter cold.

Absolute humidity is highest in midsummer. Sticky spells arrive when warm, moist air pushes in from the south or southeast, often with thunderstorms: Summer heat and Rain. Those days are less common than Mediterranean humidity seasons, but unairconditioned Finnish flats still trap the moisture.

Fog is most common in autumn in southern and southwestern Finland, often at night and early morning. FMI also describes an early-winter fog corridor roughly 40 to 80 km inland from the coast, so Espoo- and Vantaa-side mornings can feel thicker than a dry inland courtyard in Tampere: Living in Tampere and Living in Turku.

Ask about ventilation, bathroom fans, and drying space before you sign a panel-block or older wooden-house lease: How to rent a home. Closed flats with wet coats all winter need a dehumidifier plan, especially when heating is metered separately: Utilities, internet and transport.

Coast wind can make damp air feel raw even when relative humidity is already high: Wind. Snowmelt and rain-sleet cycles load entrances further: Snow. National framing: Weather in Finland and Best climate.