Month by month
| Month | Afternoon | Sea | Rain | Verdict |
|---|---|---|---|---|
| January | -1.9 °C | 2.1 °C | 13 days | Unfavourable season |
| February | -0.6 °C | 1 °C | 11 days | Unfavourable season |
| March | 2.6 °C | 1.1 °C | 11 days | Unfavourable season |
| April | 8.6 °C | 2.8 °C | 10 days | Unfavourable season |
| May | 15.7 °C | 7.4 °C | 9 days | Possible, with trade-offs |
| June | 20.6 °C | 13.1 °C | 11 days | Pleasant — a good time to go |
| July | 21.5 °C | 16.8 °C | 14 days | Pleasant — a good time to go |
| August | 20.7 °C | 17.6 °C | 13 days | Pleasant — a good time to go |
| September | 15.7 °C | 15.4 °C | 11 days | Possible, with trade-offs |
| October | 8.7 °C | 11.2 °C | 12 days | Unfavourable season |
| November | 3.8 °C | 7.8 °C | 14 days | Unfavourable season |
| December | 0.5 °C | 4.7 °C | 14 days | Unfavourable season |
Before you go
Three things to check once you have picked your dates.
Entry
Finland is in the European Union. Entry rules depend on your nationality — check before booking.
Safety
No specific restrictions
Usual precautions apply.
Official advice updated 11 August 2026
Health
Recommended vaccinations, water quality, mosquitoes: advice depends on the country and the season. Some vaccines need time before departure.
Beau Fixe is not a safety or health authority. These notes summarise public advisories and link to their source; only the competent authorities are authoritative. Alert levels: Foreign, Commonwealth & Development Office (gov.uk), Open Government Licence v3.0.
FAQ
Can you swim in Porvoo in December?
The sea averages 4.7°C in December — too cold for most swimmers.
How hot is Porvoo in December?
Expect 0.5°C in the afternoon and -3.7°C at night, averaged over the last 10 years.
Does it rain a lot in Porvoo in December?
Around 14 days with rain (≥ 1 mm) in the month — 46% of days.