Helsinki
Finland
Long-term weather forecast
Long-term weather forecast

May weather forecast and climate
Helsinki, Finland

A scenic reflection in the water of the illuminated city of Helsinki in Finland, viewed from the water
A scenic reflection in the water of the illuminated city of Helsinki in Finland, viewed from the water
The last month of the spring, May, is a mild month in Helsinki, Finland, with average temperature fluctuating between 6.3°C (43.3°F) and 14.4°C (57.9°F).

Temperature

In Helsinki, the average high-temperature increases, from a frosty 7.6°C (45.7°F) in April, to a moderate 14.4°C (57.9°F). The average low-temperature, in Helsinki, is 6.3°C (43.3°F).

Rainfall

In May, in Helsinki, the rain falls for 11 days. Throughout May, 37mm (1.5") of precipitation is accumulated. Throughout the year, in Helsinki, there are 182 rainfall days, and 655mm (25.8") of precipitation is accumulated.

Snowfall

In Helsinki, Finland, during the entire year, snow aggregates up to 740mm (29.1").

Sea temperature

In Helsinki, Finland, the average seawater temperature in May is 5°C (41°F). At temperatures below 10°C (50°F), swimming in a suitably protected swimsuit is feasible; otherwise, cold shock and loss of breathing control are imminent. Even a short swim, without thermal protection, at temperatures around 13°C (55.4°F) is not comfortable.

Daylight

In Helsinki, the average length of the day is 17.2h.

Sunshine

In May, the average sunshine is 9.2h.

UV index

The average daily maximum UV index in Helsinki, Finland, is 4. A UV Index value of 3 to 5 symbolizes a medium health hazard from unsafe exposure to the UV radiation for the average person.
In May, the average maximum UV index of 4 translate into the following recommendations:
Take precautions. Light skin individuals may get burned in less than 30 minutes. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. A wide-brim hat offers excellent sun protection for eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun.

What is the temperature in May in Helsinki?

In May, in Helsinki, Finland, the average high-temperature is 14.4°C (57.9°F), and the average low-temperature is 6.3°C (43.3°F).

How many days does it rain in May in Helsinki?

In Helsinki, Finland, in May, it is raining for 11 days, with typically 37mm (1.5") of accumulated precipitation.

What is the water temperature in May in Helsinki?

In Helsinki, Finland, the average seawater temperature in May is 5°C (41°F). Swimming in 5°C (41°F) is considered dangerous. Unprotected immersion in temperatures below 10°C (50°F) causes quickly maximum intensity cold shock with hyperventilation.

How many hours of daylight does Helsinki have in May?

The average length of the day in May in Helsinki, Finland, is 17.2h.

How many hours of sunshine does Helsinki have in May?

The average sunshine in May is 9.2h.

What is the UV index intensity in May in Helsinki?

In May, the average daily maximum UV index in Helsinki is 4. A UV Index reading of 3 to 5 represents a medium hazard to health from unprotected exposure to the UV radiation.
Average temperature in May - Helsinki, Finland
  • Average high temperature in May: 14.4°C

The warmest month (with the highest average high temperature) is July (21.5°C).
The month with the lowest average high temperature is February (-1.9°C).

  • Average low temperature in May: 6.3°C

The month with the highest average low temperature is July (14.2°C).
The coldest month (with the lowest average low temperature) is February (-7.4°C).

Average rainfall in May - Helsinki, Finland
  • Average rainfall in May: 37mm

The wettest month (with the highest rainfall) is August (80mm).
The driest month (with the lowest rainfall) is April (32mm).

Average rainfall days in May - Helsinki, Finland
  • Average rainfall days in May: 11 days

The month with the highest number of rainy days is December (20 days).
Months with the lowest number of rainy days are April and May (11 days).

Average snowfall in May - Helsinki, Finland
  • Average snowfall in May: 0mm

The month with the highest snowfall is February (230mm).
Months with the lowest snowfall are April, May, June, July, August, September and October (0mm).

Average sea temperature in May - Helsinki, Finland
  • Average sea temperature in May: 5°C

The best month for swimming (with the highest average sea temperature) is August (16°C).
Coldest months (with the lowest average sea temperature) are February and March (1°C).

Average daylight in May / Average sunshine in May - Helsinki, Finland
  • Average daylight in May: 17.2h

The month with the longest days is June (Average daylight: 18.8h).
The month with shortest days is December (Average daylight: 6h).

  • Average sunshine in May: 9.2h

The month with most sunshine is June (Average sunshine: 9.9h).
The month with least sunshine is December (Average sunshine: 0.9h).

Average UV index in May - Helsinki, Finland
  • Average UV index in May: 4

Months with the highest UV index are June and July (UV index 5).
Months with the lowest UV index are January, February, November and December (UV index 0).