Last updated: August 23, 2025
In December, the average temperature in Yli-Ii, Finland hovers around -5°C (23°F). Expect chilly extremes, with minimums plunging to -26°C (-15°F) and a maximum reaching 4°C (39°F). During this time, precipitation totals about 63 mm (2.5 in) over 15 days, and with an average humidity of an astonishing 99%, the air is bound to feel frosty and damp.
In December in Yli-Ii, the average temperature is -5°C (23°F), with maximums reaching 4°C (39°F) and minimums dropping as low as -26°C (-15°F). Travelers should be prepared for cold weather and dress warmly when visiting during this time.
In Yli-Ii in December, the precipitation amount is 63 mm (2.5 in) over a period of 15 days.
In Yli-Ii in December humidity is 99%. With an average temperature of -5°C (23°F), this humidity feels like an icy veil clinging to your skin, making every breath feel sharp and heavy, a stark reminder that even in the cold, moisture hangs in the air, creating an uncomfortable chill that can dampen any travel adventure.
In Yli-Ii 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 Yli-Ii.
UV Risk Categories
Weather in Yli-Ii varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Yli-Ii, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -8°C (18°F) | 45 mm (1.8 inches) | 100% | low |
| February Weather | -9°C (17°F) | 42 mm (1.7 inches) | 98% | low |
| March Weather | -4°C (25°F) | 46 mm (1.8 inches) | 95% | low |
| April Weather | 1°C (34°F) | 41 mm (1.6 inches) | 87% | moderate |
| May Weather | 7°C (45°F) | 51 mm (2.0 inches) | 81% | moderate |
| June Weather | 14°C (58°F) | 66 mm (2.6 inches) | 77% | high |
| July Weather | 17°C (63°F) | 77 mm (3.0 inches) | 79% | high |
| August Weather | 14°C (58°F) | 95 mm (3.7 inches) | 84% | moderate |
| September Weather | 9°C (49°F) | 76 mm (3.0 inches) | 90% | moderate |
| October Weather | 4°C (39°F) | 86 mm (3.4 inches) | 95% | low |
| November Weather | -1°C (30°F) | 67 mm (2.6 inches) | 95% | low |
| December Weather | -5°C (23°F) | 63 mm (2.5 inches) | 99% | low |