Last updated: June 24, 2025
In December, the average temperature in Fairfield, United States hovers around -2°C (28°F), with temperatures ranging from a frigid -30°C (-21°F) to a surprisingly warm 20°C (67°F). Expect 23 mm (0.9 in) of precipitation over about 6 days, coupled with a high average humidity of 90%.
In December in Fairfield, the average temperature is -2°C (28°F), with maximums reaching 20°C (67°F) and minimums plummeting to as low as -30°C (-21°F). Travelers should be prepared for a wide range of temperatures and dress accordingly for potential cold weather.
In Fairfield in December, the precipitation amount is 23 mm (0.9 in) spread over 6 days.
In Fairfield in December humidity is 90%. With an average temperature of -2°C (28°F), this humidity feels like stepping into a frosty haze that clings to your skin, making every breath feel chilled and heavy, while your body battles the dampness in the air—a stark reminder of how difficult it can be to travel comfortably in such conditions.
In Fairfield 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 Fairfield, you can visit Hourly UV Index in Fairfield.
UV Risk Categories
Weather in Fairfield varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Fairfield, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -4°C (25°F) | 13 mm (0.5 inches) | 87% | low |
| February Weather | -7°C (19°F) | 35 mm (1.4 inches) | 88% | moderate |
| March Weather | 0°C (33°F) | 25 mm (1.0 inches) | 83% | moderate |
| April Weather | 5°C (41°F) | 54 mm (2.1 inches) | 78% | high |
| May Weather | 12°C (53°F) | 75 mm (2.9 inches) | 76% | very high |
| June Weather | 17°C (63°F) | 80 mm (3.1 inches) | 78% | very high |
| July Weather | 21°C (71°F) | 9 mm (0.4 inches) | 77% | very high |
| August Weather | 20°C (68°F) | 20 mm (0.8 inches) | 71% | very high |
| September Weather | 14°C (58°F) | 38 mm (1.5 inches) | 68% | high |
| October Weather | 6°C (44°F) | 33 mm (1.3 inches) | 72% | moderate |
| November Weather | 2°C (36°F) | 24 mm (0.9 inches) | 84% | moderate |
| December Weather | -2°C (28°F) | 23 mm (0.9 inches) | 90% | low |