December is a popular month to ask about Hietaniemi because conditions can shift week to week along this coast. Expect the water near 16.0°C, with daily variation from wind, tides and recent storms. We refresh the live value from Open-Meteo Marine every hour, so the headline above always reflects the current state of the Baltic Sea.
Hietaniemi sea temperature in December — averages 16.0°C
The sea at Hietaniemi in Finland averages 16.0°C during December, based on long-run climatology for the Baltic Sea. Use the live reading below for today's actual water and the monthly grid to compare with the rest of the year.
Average sea · December
16.0°C
mild · Fair
Live water now
…
Recommended wetsuit
3/2mm fullsuit
At 16.0°C a 3/2mm fullsuit is the standard wetsuit for surfing and watersports.
Monthly comparison
Yes, but expect a fresh dip · Hietaniemi
Can you swim at Hietaniemi in June? — 22.0°C water22.0°CCan you swim at Hietaniemi in July? — 25.0°C water25.0°CCan you swim at Hietaniemi in August? — 26.0°C water26.0°CCan you swim at Hietaniemi in September? — 24.0°C water24.0°CCan you swim at Hietaniemi in October? — 21.0°C water21.0°CCan you swim at Hietaniemi in November? — 18.0°C water18.0°C
Frequently asked questions
What is the average sea temperature at Hietaniemi in December?
Hietaniemi averages 16.0°C in December, based on long-run climatology for the Baltic Sea.
Is the sea warm enough to swim at Hietaniemi in December?
It is swimmable but fresh; confident swimmers will be fine without a wetsuit.
Do I need a wetsuit at Hietaniemi in December?
A 2 mm shorty is comfortable for sessions over 30 minutes.