Last updated: June 24, 2025
In December, the average temperature in Rock Valley, United States hovers around -3°C (27°F), with minimums plummeting to -23°C (-10°F) and peaks reaching 17°C (62°F). Expect 39 mm (1.5 in) of precipitation spread over 4 days, while the air maintains a high average humidity of 83%.
In December in Rock Valley, the average temperature is -3°C (27°F), with maximums reaching 17°C (62°F) and minimums dropping as low as -23°C (-10°F). Be sure to pack warm clothing, as temperatures can vary widely during this time of year.
In Rock Valley in December, the precipitation amount is 39 mm (1.5 in) spread over a period of 4 days.
In Rock Valley in December humidity is 83%. With an average temperature of -3°C (27°F), this humidity feels like a biting chill that wraps around you, making every breath feel heavy and the air almost damp with cold. Traveling in such conditions can be quite challenging, as the moisture in the air makes the cold penetrate deeper, making it essential to dress warmly and stay active to ward off the chill.
In Rock Valley in December, 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 Rock Valley, you can check the information here.
UV Risk Categories
Weather in Rock Valley varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Rock Valley, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -6°C (21°F) | 25 mm (1.0 inches) | 80% | low |
| February Weather | -7°C (20°F) | 29 mm (1.1 inches) | 84% | moderate |
| March Weather | 2°C (36°F) | 70 mm (2.7 inches) | 75% | moderate |
| April Weather | 7°C (45°F) | 92 mm (3.6 inches) | 79% | very high |
| May Weather | 15°C (60°F) | 133 mm (5.2 inches) | 74% | very high |
| June Weather | 23°C (73°F) | 101 mm (4.0 inches) | 81% | extreme |
| July Weather | 24°C (75°F) | 80 mm (3.2 inches) | 82% | very high |
| August Weather | 22°C (72°F) | 98 mm (3.9 inches) | 80% | very high |
| September Weather | 19°C (66°F) | 100 mm (3.9 inches) | 75% | very high |
| October Weather | 9°C (49°F) | 85 mm (3.3 inches) | 77% | moderate |
| November Weather | 2°C (35°F) | 27 mm (1.0 inches) | 85% | moderate |
| December Weather | -3°C (27°F) | 39 mm (1.5 inches) | 83% | moderate |