Last updated: June 24, 2025
In December, the average temperature in Flat River, United States hovers around 4°C (40°F), with a wide range that can dip to a minimum of -15°C (6°F) or soar to a maximum of 25°C (77°F). Expect 70 mm (2.8 in) of precipitation spread over about 7 days, adding to the average humidity of a comfortable 86%.
In December in Flat River, the average temperature is 4°C (40°F), with maximums that can reach 25°C (77°F) and minimums that can drop as low as -15°C (6°F). Be prepared for a wide range of temperatures if you're planning to travel during this time.
In Flat River in December, the precipitation amount is 70 mm (2.8 in) over a span of 7 days.
In Flat River in December humidity is 86%. With an average temperature of 4°C (40°F), this humidity feels like a damp chill that seeps into your bones, making outdoor activities uncomfortable and travel cumbersome as you navigate through a thick, heavy air that clings to your skin.
In Flat River 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 Flat River, you can check the information here.
UV Risk Categories
Weather in Flat River varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Flat River, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | 1°C (34°F) | 80 mm (3.2 inches) | 83% | moderate |
| February Weather | 3°C (37°F) | 100 mm (3.9 inches) | 81% | high |
| March Weather | 9°C (48°F) | 134 mm (5.3 inches) | 80% | high |
| April Weather | 13°C (55°F) | 171 mm (6.7 inches) | 80% | very high |
| May Weather | 19°C (66°F) | 150 mm (5.9 inches) | 83% | extreme |
| June Weather | 24°C (75°F) | 90 mm (3.5 inches) | 83% | extreme |
| July Weather | 26°C (79°F) | 87 mm (3.4 inches) | 76% | extreme |
| August Weather | 24°C (76°F) | 119 mm (4.7 inches) | 69% | very high |
| September Weather | 22°C (71°F) | 66 mm (2.6 inches) | 68% | very high |
| October Weather | 15°C (59°F) | 115 mm (4.5 inches) | 72% | high |
| November Weather | 7°C (45°F) | 75 mm (3.0 inches) | 83% | moderate |
| December Weather | 4°C (40°F) | 70 mm (2.8 inches) | 86% | moderate |