Last updated: June 24, 2025
In Jefferson, United States, the average temperature in December hovers around 1°C (35°F). While chilly days can see temperatures plummet to a frigid -17°C (2°F), the mercury can occasionally rise to a mild 17°C (63°F). Expect 103 mm (4.1 in) of precipitation spread over 16 days, contributing to an average humidity of 86%.
In December in Jefferson, the average temperature is 1°C (35°F). Maximum temperatures can reach 17°C (63°F), while minimums may drop to as low as -17°C (2°F). Be prepared for a wide range of temperatures during your travels to Jefferson this December.
In Jefferson in December, the precipitation amount is 103 mm (4.1 in) spread over 16 days.
In Jefferson in December, humidity is 86%. With an average temperature of 1°C (35°F), this humidity feels like a biting chill that wraps around you, making outdoor exploration uncomfortable and requiring extra layers to stay warm while navigating the damp air.
In Jefferson in December, the maximum UV index is 2, which corresponds to a low exposure category. With this level of UV radiation, the time to burn is approximately 45 minutes. To learn more about the hourly UV index in Jefferson, you can visit Hourly UV Index in Jefferson.
UV Risk Categories
Weather in Jefferson varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Jefferson, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -2°C (29°F) | 91 mm (3.6 inches) | 88% | moderate |
| February Weather | -1°C (31°F) | 94 mm (3.7 inches) | 88% | moderate |
| March Weather | 3°C (38°F) | 97 mm (3.8 inches) | 87% | high |
| April Weather | 8°C (47°F) | 114 mm (4.5 inches) | 87% | very high |
| May Weather | 15°C (59°F) | 128 mm (5.0 inches) | 81% | very high |
| June Weather | 20°C (68°F) | 123 mm (4.8 inches) | 83% | very high |
| July Weather | 23°C (73°F) | 145 mm (5.7 inches) | 82% | very high |
| August Weather | 22°C (71°F) | 101 mm (4.0 inches) | 76% | very high |
| September Weather | 19°C (66°F) | 92 mm (3.6 inches) | 77% | very high |
| October Weather | 13°C (56°F) | 127 mm (5.0 inches) | 82% | high |
| November Weather | 5°C (41°F) | 108 mm (4.2 inches) | 89% | moderate |
| December Weather | 1°C (35°F) | 103 mm (4.1 inches) | 86% | low |