Last updated: June 24, 2025
In December, the average temperature in Eureka, United States hovers around 1°C (34°F). Expect a chilly range, with minimums dipping to -21°C (-5°F) and maximums soaring to 20°C (68°F). The month brings a moderate precipitation of 55 mm (2.2 in) across about 7 days, paired with an average humidity of a brisk 84%. Prepare for a mix of cold and wet conditions!
In December in Eureka, the average temperature is 1°C (34°F). The maximum can reach 20°C (68°F) and the minimum can be as low as -21°C (-5°F). This variation in temperatures makes Eureka an intriguing destination for travelers, offering a mix of chilly days and surprisingly warm spells.
In Eureka in December, the precipitation amount is 55 mm (2.2 in) over the course of 7 days.
In Eureka in December humidity is 84%. With an average temperature of 1°C (34°F), this humidity feels like a biting chill that seeps into your bones, making travel uncomfortable and requiring extra layers to keep warm while navigating the damp air.
In Eureka 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 Eureka, you can visit Hourly UV Index in Eureka.
UV Risk Categories
Weather in Eureka varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Eureka, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -3°C (27°F) | 61 mm (2.4 inches) | 82% | moderate |
| February Weather | -2°C (29°F) | 68 mm (2.7 inches) | 83% | moderate |
| March Weather | 5°C (42°F) | 106 mm (4.2 inches) | 84% | high |
| April Weather | 10°C (51°F) | 117 mm (4.6 inches) | 85% | very high |
| May Weather | 18°C (64°F) | 165 mm (6.5 inches) | 79% | very high |
| June Weather | 23°C (74°F) | 138 mm (5.4 inches) | 82% | extreme |
| July Weather | 25°C (77°F) | 109 mm (4.3 inches) | 80% | very high |
| August Weather | 23°C (74°F) | 80 mm (3.1 inches) | 81% | very high |
| September Weather | 21°C (70°F) | 69 mm (2.7 inches) | 80% | very high |
| October Weather | 13°C (56°F) | 130 mm (5.1 inches) | 82% | high |
| November Weather | 4°C (40°F) | 56 mm (2.2 inches) | 88% | moderate |
| December Weather | 1°C (34°F) | 55 mm (2.2 inches) | 84% | low |