Last updated: August 23, 2025
In December, the average temperature in Seinaejoki, Finland hovers around -3°C (28°F). However, temperatures can vary drastically, plunging to a chilling -26°C (-15°F) at the low end and peaking at a mild 5°C (42°F). Expect 47 mm (1.9 in) of precipitation spread over 13 days, wrapped in an atmosphere of high average humidity at 95%.
In December in Seinaejoki, the average temperature is -3°C (28°F). The maximum can reach 5°C (42°F), while the minimum can plummet to as low as -26°C (-15°F). Be prepared for extremely cold weather and dress accordingly if you're planning to travel during this time.
In Seinaejoki in December, the total precipitation amount is 47 mm (1.9 in), spread over 13 days.
In Seinaejoki in December humidity is 95%. With an average temperature of -3°C (28°F), this humidity feels like a biting chill that seeps into your bones, making outdoor travels uncomfortable and urging you to seek warmth and shelter more quickly than you anticipated.
In Seinaejoki in December, the maximum UV index is 1, which corresponds to a low Exposure Category. This means you have a time to burn of 45 minutes. For more details, you can check the Hourly UV Index in Seinaejoki.
UV Risk Categories
Weather in Seinaejoki varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Seinaejoki, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -4°C (24°F) | 37 mm (1.4 inches) | 97% | low |
| February Weather | -5°C (22°F) | 39 mm (1.5 inches) | 95% | low |
| March Weather | -2°C (29°F) | 41 mm (1.6 inches) | 92% | moderate |
| April Weather | 3°C (38°F) | 44 mm (1.7 inches) | 85% | moderate |
| May Weather | 9°C (49°F) | 60 mm (2.3 inches) | 77% | moderate |
| June Weather | 15°C (60°F) | 61 mm (2.4 inches) | 74% | high |
| July Weather | 17°C (63°F) | 59 mm (2.3 inches) | 79% | high |
| August Weather | 15°C (59°F) | 90 mm (3.6 inches) | 82% | moderate |
| September Weather | 10°C (50°F) | 71 mm (2.8 inches) | 89% | moderate |
| October Weather | 5°C (41°F) | 75 mm (2.9 inches) | 93% | low |
| November Weather | 1°C (34°F) | 58 mm (2.3 inches) | 93% | low |
| December Weather | -3°C (28°F) | 47 mm (1.9 inches) | 95% | low |