Helsinki Weather in May
Finland · Subarctic climate · Data averaged from 2020-01-01 to 2024-12-31 (5 years)
May in Helsinki sees average temperatures ranging from a low of 5.5°C (41.9°F) to a high of 13.4°C (56.1°F), with a mean of 9.7°C (49.5°F). Compared to the annual average of 6.8°C (44.2°F), this month is 2.9°C warmer than the yearly norm. Precipitation averages 51.0mm, making it approximately 18.0mm drier than the monthly average of 69.0mm. The city receives an average of 12.9 hours of sunshine per day during May, with relative humidity averaging 68.8%. Wind speeds reach an average maximum of 21.3 km/h. Snowfall averages 0.7cm during May, which can affect travel plans and outdoor activities. For travelers, this month offers a temperature experience in Helsinki, with drier-than-average conditions compared to the rest of the year.
If you're planning outdoor activities in Helsinki, daylight is the variable that matters most. I did a sea kayak tour in June at 10pm — full sun, 18°C, surreal. December gives you 6 hours of gray light, which limits everything. The Nordic summer (June-August) is the outdoor window: 18-22°C, 19 hours of daylight, perfect for island-hopping by ferry. Winter is its own adventure: -5°C, snow cover from January-March, and the sauna-ice-swim cycle is a Helsinki essential. Pack windproof layers year-round — the Baltic breeze cuts hard. September brings fall colors and fewer tourists; my favorite hiking month.
May vs Adjacent Months
| Metric | April | May | June |
|---|---|---|---|
| Mean Temp | 3.6°C (38.5°F) | 9.7°C (49.5°F) | 16.7°C (62.1°F) |
| Rainfall | 46.1mm | 51.0mm | 49.8mm |
| Sunshine | 10.0 hrs | 12.9 hrs | 15.6 hrs |
| Humidity | 74.7% | 68.8% | 69.6% |
| Wind | 22.3 km/h | 21.3 km/h | 20.4 km/h |
| Rainy Days | 13.2 | 13.6 | 12.0 |
| Snowfall | 12.0 cm | 0.7 cm | 0.0 cm |
Seasonal Context
May falls in Spring in the Northern Hemisphere. Spring is a transitional season with temperatures rising from winter lows. For travelers visiting Helsinki in May, the data indicates mixed conditions based on the combination of temperature, precipitation, and daylight hours.
Frequently Asked Questions
What is the average temperature in Helsinki in May?
The average temperature in Helsinki during May ranges from 5.5°C (41.9°F) to 13.4°C (56.1°F), with a mean of 9.7°C (49.5°F).
How much does it rain in Helsinki in May?
Helsinki receives an average of 51.0mm of precipitation in May, spread across approximately 13.6 rainy days.
What should I pack for Helsinki in May?
Based on May weather data, pack warm layers, a medium jacket, and waterproof outerwear.
Is May a good time to visit Helsinki?
May is a cooler month, suitable for travelers who prefer mild weather and fewer crowds. Pack warm layers and enjoy indoor attractions.
Other Months for Helsinki
Cities with Similar May Climate (Subarctic)
Data Source: Open-Meteo historical archive (2020-01-01 to 2024-12-31). Daily measurements aggregated into monthly climate normals. Coordinates: 60.17°, 24.94°. Timezone: Europe/Helsinki. Last updated: 2026-07-30.