Weather in Helsinki for September 2025
In general, the average temperature in Helsinki at the beginning of September is 18.7 °C. As the month progressed, temperatures tended to significantly cool down, reaching an average of 15.4 °C by the end of September.
The climate of Helsinki in September is notably wet, with an average of 13 rainy days.
Is September a good time to visit Helsinki? check out the best time to travel to Helsinki page.
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Helsinki in September average weather
Mon. | Tue. | Wed. | Thu. | Fri. | Sat. | Sun. |
---|---|---|---|---|---|---|
1 17° | 2 17° | 3 19° | 4 20° | 5 21° | 6 18° | 7 19° |
8 20° | 9 20° | 10 20° | 11 19° | 12 19° | 13 18° | 14 17° |
15 16° | 16 18° | 17 18° | 18 15° | 19 19° | 20 18° | 21 17° |
22 15° | 23 15° | 24 17° | 25 16° | 26 16° | 27 16° | 28 16° |
29 14° | 30 13° |
You can click on date
Temperatures trend during September in Helsinki
September weather day by day
Date | Weather | Temperatures | Rain | UV | More |
---|---|---|---|---|---|
1 Sept. | Light rain shower | 17° /12° | 4.3 mm | 4 | |
2 Sept. | Light rain shower | 17° /12° | 7.4 mm | 4 | |
3 Sept. | Light rain shower | 19° /13° | 1.4 mm | 5 | |
4 Sept. | Cloudy | 20° /13° | 0 mm | 5 | |
5 Sept. | Patchy rain possible | 21° /13° | 0.3 mm | 5 | |
6 Sept. | Sunny | 18° /12° | 0 mm | 6 | |
7 Sept. | Partly cloudy | 19° /11° | 0 mm | 6 | |
8 Sept. | Cloudy | 20° /14° | 0 mm | 5 | |
9 Sept. | Overcast | 20° /14° | 0 mm | 5 | |
10 Sept. | Cloudy | 20° /14° | 1.2 mm | 5 | |
11 Sept. | Sunny | 19° /14° | 4.8 mm | 5 | |
12 Sept. | Sunny | 19° /14° | 0.1 mm | 5 | |
13 Sept. | Moderate rain | 18° /13° | 17 mm | 4 | |
14 Sept. | Overcast | 17° /11° | 11.1 mm | 4 | |
15 Sept. | Overcast | 16° /10° | 1.4 mm | 4 | |
16 Sept. | Overcast | 18° /11° | 0 mm | 4 | |
17 Sept. | Light rain shower | 18° /10° | 0.9 mm | 5 | |
18 Sept. | Overcast | 15° /8° | 0 mm | 4 | |
19 Sept. | Light rain shower | 19° /11° | 0.9 mm | 5 | |
20 Sept. | Light rain shower | 18° /11° | 1.6 mm | 5 | |
21 Sept. | Patchy rain possible | 17° /11° | 0 mm | 5 | |
22 Sept. | Sunny | 15° /10° | 0 mm | 5 | |
23 Sept. | Light rain shower | 15° /10° | 5.3 mm | 4 | |
24 Sept. | Patchy rain possible | 17° /12° | 0.6 mm | 5 | |
25 Sept. | Overcast | 16° /11° | 1.5 mm | 4 | |
26 Sept. | Patchy rain possible | 16° /12° | 10.1 mm | 4 | |
27 Sept. | Patchy rain possible | 16° /12° | 8.8 mm | 4 | |
28 Sept. | Mist | 16° /10° | 11.7 mm | 4 | |
29 Sept. | Partly cloudy | 14° /9° | 0.3 mm | 4 | |
30 Sept. | Light rain shower | 13° /8° | 1.7 mm | 4 | |
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Helsinki in September - FAQ
What to pack to Helsinki in September?
As you prepare for your trip to Helsinki in September, it's important to consider the typical weather patterns for the time of year. Below is a carefully tailored packing list to ensure that your time in Helsinki, during September, is comfortable and enjoyable, regardless of the weather conditions.
- Clothing
- Warm Clothing: Sweaters, hoodies, long pants
- Rain Gear: Lightweight, waterproof clothing
- Footwear
- Waterproof Shoes
- Accessories
- Scarves: To protect you from the cold wind
- Gloves/Mittens: Essential for cold weather
- Warm Hats: Warm hats for insulation in cold weather
- Umbrellas/Raincoats: For rainy days
Quick links
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