Hietaniemi Water Temperature & Swim Forecast
Helsinki's main summer city beach.
Cool water with a light chop and a light breeze — fresh conditions — a wetsuit is recommended.
Model estimate · modelled, not a buoy measurement. How accurate is this?
Location
Hietaniemi on the map, with nearby beaches and live sea temperatures.
7-day forecast
Water, air, waves, wind and UV outlook for the week ahead.
4/3mm fullsuit
At 15.2°C you need a 4/3mm fullsuit, and many surfers add neoprene boots.
- + Optional 3mm boots
Recommendation tuned for Hietaniemi's current water temperature. Individual tolerance, wind chill, and session length all matter — when in doubt, size up.
Hietaniemi swimming conditions summary
- Water temperature
- 15.2°C
- Water feels
- Refreshing
- Swimmable today
- Only with thermal protection
- Swim conditions score
- 54/100 · Fair
- Wetsuit needed
- 4/3mm fullsuit
- Air temperature
- —
- Waves
- —
- Wind
- —
- UV index
- —
- Average sea temperature (September)
- 15.0 °C
- Warmest months to swim
- July, August, September
At 15.2°C you need a 4/3mm fullsuit, and many surfers add neoprene boots. Model estimate. Water, wave, wind and UV values are Open-Meteo marine/weather model estimates, refreshed hourly — not buoy measurements.
Frequently asked questions
Can I swim at Hietaniemi right now?
The sea at Hietaniemi is currently 15.2°C — cold swimming conditions. Most swimmers will find the water comfortable when it's above 22°C; below 18°C feels fresh and a wetsuit is recommended.
What will the sea temperature be at Hietaniemi next week?
Based on long-term September averages and the latest marine model, expect the sea around Hietaniemi to sit close to 12.1°C over the next 7 days. Check the live 7-day chart above for the exact daily outlook.
When is the best month to swim at Hietaniemi?
July – August – September are typically the warmest months to swim at Hietaniemi, with sea temperatures at their seasonal peak.
Do I need a wetsuit at Hietaniemi?
With water currently at 15.2°C: above 22°C no wetsuit needed; 18–22°C a shorty is comfortable for long swims; 14–18°C a 3/2mm full suit; below 14°C a 4/3mm or thicker.
Can I swim at Hietaniemi today?
The sea is currently 15.2°C — fair swimming conditions. Acclimatised swimmers will be most comfortable.
- • Located in Finnish Coast, Finland (Baltic Sea).
- • Family friendly with calm, accessible water.
- • Live data refreshed hourly from Open-Meteo Marine.
Monthly sea temperature averages
Tap any month to see what to expect — based on regional climatology.
Best time to swim in Hietaniemi
The sea in Hietaniemi peaks in August, when the water averages around 17°C.
On average, 0 months a year sit above 20°C — the threshold most swimmers describe as pleasant without a wetsuit.
Outside peak season the water drops toward 6°C, so a 3/2mm shorty or full wetsuit makes long swims much more comfortable.
The coldest month is typically February at around 3°C, when cold-water swimmers dominate the coast.
Hietaniemi sea temperature history
Long-term climatology for Hietaniemi shows an annual mean sea temperature of 9°C, ranging from 3°C in winter to 17°C at the summer peak.
The seasonal swing is roughly 14°C between the coldest and warmest month — a useful yardstick when comparing years or checking whether the current sea is running above or below average.
Recent decades have trended slightly warmer at Hietaniemi, in line with regional sea-surface temperature records for the wider basin.
Monthly averages below are drawn from multi-decadal climatology and are updated as new observations arrive.
Hietaniemi sea temperature: frequently asked questions
What is the warmest month to swim in Hietaniemi?
August is the warmest month in Hietaniemi, when the sea averages about 17°C. Late-season warmth often persists a few weeks after peak.
When is the sea coldest in Hietaniemi?
The coldest month in Hietaniemi is typically February, when the water averages around 3°C. Cold-water swimmers and surfers dominate this period.
When can you swim in Hietaniemi without a wetsuit?
The sea in Hietaniemi rarely climbs above 20°C, so a wetsuit is recommended year-round for anything longer than a quick dip.
Do I need a wetsuit in Hietaniemi?
Outside peak summer the water in Hietaniemi drops toward 6°C, so a 3/2mm shorty or full wetsuit makes long swims much more comfortable. In peak months most swimmers go without.
What is the average sea temperature in Hietaniemi?
The long-term annual mean sea temperature in Hietaniemi is about 9°C, based on multi-decadal climatology of the surrounding waters.
How do I check the current sea temperature in Hietaniemi?
The live reading at the top of this page shows the current sea temperature in Hietaniemi, updated hourly from marine buoy and satellite data. The 7-day forecast covers water, air, waves, wind and UV for the week ahead.
Year-round sea temperature
| Month | Sea | Comfort |
|---|---|---|
| Jan | 4°C | Cold |
| Feb | 3°C | Cold |
| Mar | 3°C | Cold |
| Apr | 5°C | Cold |
| May | 9°C | Cold |
| Jun | 13°C | Cold |
| Jul | 16°C | Bracing |
| Aug ⭐ | 17°C | Bracing |
| Sep | 15°C | Bracing |
| Oct | 11°C | Cold |
| Nov | 7°C | Cold |
| Dec | 5°C | Cold |
Nearby beaches
The closest coastline, with live water temperatures.