Helsinki Weather in September

With daytime temperatures of 16°C (61°F) and nighttime lows of 8°C (46°F), September in Helsinki brings moderate temperatures during the day. Do keep in mind that quite a bit of rainfall is typical. Around 64 mm (2.5 in) falls on average.

Rainfall in Helsinki in September

Looking at the last 30 years, the data shows about 17 days with rain, averaging 64 mm (2.5 in) for the month. With rain spread across many days but low totals, showers are typically short and light rather than heavy.

Temperature in Helsinki in September

September in Helsinki brings typical temperatures with highs around 16°C (61°F) and lows of 8°C (46°F). Conditions are often most pleasant around the middle of the day. At 8°C (46°F) overnight, it gets properly cold after dark. On the bright side, cold nights tend to make for excellent sleeping conditions.

Sunshine in Helsinki in September

The area enjoys a moderate level of sunlight, with around 151 hours. It's a good balance between sunny and cloudy days.

Wind Speed in Helsinki in September

Wind speeds average 3 m/s (6 knots) during September. At this speed, light breezes keep leaves and small twigs in gentle motion while the wind also provides natural cooling. Since this is an average, some days are more tranquil while others have more persistent light winds that are more noticeable.

Average water temperature in September

The water temperature is 13°C (55°F), chilly, but perfectly fine for a swim if you're not too sensitive to cold water. A short wetsuit can make longer sessions more comfortable.

For Helsinki itself, June, July and August generally stand out with the best circumstances. If you're seeking pleasant, dry and sunny weather somewhere else in the world, our weather planner can help you explore other options.