Last updated: August 23, 2025
In Sievi, Finland, the average temperature in September hovers around 10°C (49°F). Temperatures can range from a chilly -5°C (24°F) to a pleasant 24°C (75°F). Expect about 76 mm (3.0 in) of precipitation spread over 13 days, with an average humidity of 89%. Stay prepared for a mix of weather as you explore this vibrant destination!
In September in Sievi, the average temperature is 10°C (49°F). The maximum can reach 24°C (75°F), and the minimum can be as low as -5°C (24°F). Travelers should be prepared for a wide range of temperatures and pack accordingly.
In Sievi in September, the total precipitation amount is 76 mm (3.0 in), which occurs over the course of 13 days.
In Sievi in September, humidity is 89%. With an average temperature of 10°C (49°F), this humidity feels like a damp chill that penetrates your clothes and makes outdoor activities uncomfortable, often leaving travelers feeling clammy and in need of extra layers to stay warm.
In Sievi in September, the maximum UV index is 3, which corresponds to a moderate Exposure Category. The time to burn is approximately 30 minutes. For more details on the hourly UV index in Sievi, you can check the information here.
UV Risk Categories
Weather in Sievi varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Sievi, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -6°C (21°F) | 37 mm (1.5 inches) | 97% | low |
| February Weather | -7°C (20°F) | 40 mm (1.6 inches) | 95% | low |
| March Weather | -3°C (27°F) | 37 mm (1.5 inches) | 92% | low |
| April Weather | 2°C (36°F) | 39 mm (1.5 inches) | 85% | moderate |
| May Weather | 8°C (47°F) | 58 mm (2.3 inches) | 77% | moderate |
| June Weather | 15°C (59°F) | 56 mm (2.2 inches) | 74% | high |
| July Weather | 17°C (63°F) | 72 mm (2.9 inches) | 79% | high |
| August Weather | 14°C (58°F) | 91 mm (3.6 inches) | 82% | moderate |
| September Weather | 10°C (49°F) | 76 mm (3.0 inches) | 89% | moderate |
| October Weather | 4°C (40°F) | 83 mm (3.3 inches) | 93% | low |
| November Weather | 0°C (32°F) | 59 mm (2.3 inches) | 93% | low |
| December Weather | -4°C (25°F) | 48 mm (1.9 inches) | 95% | low |