Naantali
Finland
Long-term weather forecast
Long-term weather forecast

Monthly weather forecast and climate
Naantali, Finland

In January, the average sea temperature in Naantali, Finland, is 0.7°C (33.3°F). Note: For swimming, this is considered life-threatening and very dangerous. Weather in January »
With an average sea temperature of -0.4°C (31.3°F), February is the month with the coldest seawater in Naantali, Finland. Note: For swimming, this is considered very dangerous and immediately life-threatening. Weather in February »

In March, the average sea temperature in Naantali, Finland, is -0.3°C (31.5°F). Note: For swimming, this is considered very dangerous and immediately life-threatening. Weather in March »

In Naantali, Finland, the average seawater temperature in April is 0.5°C (32.9°F). Note: For swimming, this is considered very dangerous and immediately life-threatening. Weather in April »

In May, the average sea temperature in Naantali, Finland, is 3.8°C (38.8°F). Note: For swimming, this is considered extremely cold, dangerous, and life-threatening. Weather in May »

In Naantali, Finland, in June, the average water temperature is 8.9°C (48°F). Note: Swimming in 8.9°C (48°F) is considered life-threatening. Even a few minutes in 13°C (55.4°F) water is uncomfortable, and swimming below 10°C (50°F) may cause total loss of breathing control and cold shock, depending on a person's physique. Weather in June »

In Naantali, Finland, in July, the average water temperature is 12.4°C (54.3°F). Note: Swimming in 12.4°C (54.3°F) is considered life-threatening. Even a few minutes in 13°C (55.4°F) water is uncomfortable, and swimming below 10°C (50°F) may cause total loss of breathing control and cold shock, depending on a person's physique. Weather in July »

With an average sea temperature of 12.8°C (55°F), August is the month with the warmest seawater in Naantali, Finland. Note: Swimming in 12.8°C (55°F) is considered life-threatening. Weather in August »

In Naantali, Finland, the average seawater temperature in September is 10.3°C (50.5°F). Note: Swimming in 10.3°C (50.5°F) is considered dangerous. Unprotected immersion in temperatures below 10°C (50°F) causes quickly maximum intensity cold shock with hyperventilation. Weather in September »

In October, the average sea temperature in Naantali, Finland, is 6.6°C (43.9°F). Note: Swimming in 6.6°C (43.9°F) is considered dangerous. Unprotected immersion in temperatures below 10°C (50°F) causes quickly maximum intensity cold shock with hyperventilation. Weather in October »

In Naantali, Finland, the average seawater temperature in November is 4.3°C (39.7°F). Note: For swimming, this is considered extremely cold, dangerous, and life-threatening. Weather in November »

In December, the average sea temperature in Naantali, Finland, is 2.1°C (35.8°F). Note: For swimming, this is considered extremely cold, dangerous, and life-threatening. Weather in December »

When is the sea coldest in Naantali?

February is the month with the coldest seawater in Naantali, with an average sea temperature of -0.4°C (31.3°F).

When are the longest days in Naantali?

June has the longest days of the year in Naantali, with an average of 18.9h of daylight.

What is the month with the warmest sea water in Naantali?

August is the month with the warmest seawater in Naantali, with an average sea temperature of 12.8°C (55°F).

What is the month with the shortest days in Naantali?

December has the shortest days of the year, with an average of 5.9h of daylight.
Average sea temperature - Naantali, Finland

The best month for swimming (with the highest average sea temperature) is August (12.8°C).
The coldest month (with the lowest average sea temperature) is February (-0.4°C).

Average daylight - Naantali, Finland

The month with the longest days is June (Average daylight: 18.9h).
The month with shortest days is December (Average daylight: 5.9h).