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Frost dates in Finland

2 places in Finland, each with a last and first frost worked out from its own daily temperature record rather than from a regional average. Median dates are listed below; follow a town for the full distribution, the early and late years behind it, and a planting calendar built from them.

Earliest last frost

23 Apr

At Helsinki, the first place here safe to plant out.

Latest last frost

26 Apr

At Espoo. Spring arrives 3 days later there than at Helsinki.

Growing season

194–206 d

Frost-free days: shortest at Espoo, longest at Helsinki.

Hardiness zone

7a

USDA-equivalent, the same across every place listed here.

Why frost dates vary across Finland

A national figure would be no use to anyone here. The growing season runs from 194 frost-free days at Espoo to 206 at Helsinki — a difference of 12 days, which is the difference between one tomato crop and none. That is why every date on this site is calculated for one place at a time.

How to read the table

Last frost is the median date of the final spring frost: in half of the years on record the last frost fell before it, in half after. First frost is the median date of the first autumn frost, and season is the number of frost-free days between them. All three are measured at the 0 °C air-temperature threshold.

A median is a planning date, not a guarantee. Plant tender crops on it and you accept roughly a one-in-two chance of a later frost in any given year. Each town page shows the cautious date — safe in nine years out of ten — alongside it, together with the earliest and latest frost the record holds. Read how the figures are calculated.

Every place in Finland

Listed by population, because that is how most people find their own town.

Median last and first air frost at 0 °C, with the frost-free season in days and the USDA-equivalent hardiness zone. Places with no reliable frost in the record show “none”.
Place Region Last frost First frost Season Zone
Helsinki Uusimaa 23 Apr 15 Nov 206 d 7a
Espoo Uusimaa 26 Apr 5 Nov 194 d 7a

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