The temperatures in Lahti in September are quite cold with temperatures between 8°C and 15°C, warm clothes are a must.
You can expect about 3 to 8 days of rain in Lahti during the month of September. It’s a good idea to bring along your umbrella so that you don’t get caught in poor weather.
Our weather forecast can give you a great sense of what weather to expect in Lahti in September 2025.
If you’re planning to visit Lahti in the near future, we highly recommend that you review the 14 day weather forecast for Lahti before you arrive.
Temperatures
15° / 8°
Rainy Days
5
Snowy Days
0
Dry Days
25
Rainfall
62
mm
Sun Hours
7.9
Hrs
