Last updated: June 24, 2025
In Eureka, United States, the average temperature in December hovers around 4°C (40°F). Expect a chilly minimum of -16°C (4°F) and a mild maximum of 23°C (74°F). With an average precipitation of 57 mm (2.2 in) spread over 6 days, you might want to keep an umbrella handy. The air is quite humid, with an average humidity level of 86%—perfect for cozy indoor activities!
In December in Eureka, the average temperature is 4°C (40°F). Maximum temperatures can reach 23°C (74°F), while minimum temperatures can drop as low as -16°C (4°F). This wide temperature range suggests that travelers should be well-prepared for both chilly and warm conditions when visiting.
In Eureka in December, the precipitation amount is 57 mm (2.2 in) over a span of 6 days.
In Eureka 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 Eureka 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 Eureka, you can check the information here.
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 | 0°C (33°F) | 75 mm (3.0 inches) | 82% | moderate |
| February Weather | 2°C (36°F) | 81 mm (3.2 inches) | 80% | moderate |
| March Weather | 8°C (47°F) | 129 mm (5.1 inches) | 80% | high |
| April Weather | 13°C (55°F) | 124 mm (4.9 inches) | 80% | very high |
| May Weather | 19°C (67°F) | 144 mm (5.7 inches) | 82% | very high |
| June Weather | 24°C (76°F) | 88 mm (3.5 inches) | 83% | extreme |
| July Weather | 26°C (80°F) | 95 mm (3.7 inches) | 81% | very high |
| August Weather | 24°C (76°F) | 139 mm (5.5 inches) | 80% | very high |
| September Weather | 22°C (72°F) | 56 mm (2.2 inches) | 76% | very high |
| October Weather | 15°C (59°F) | 110 mm (4.3 inches) | 76% | high |
| November Weather | 7°C (45°F) | 70 mm (2.8 inches) | 85% | moderate |
| December Weather | 4°C (40°F) | 57 mm (2.2 inches) | 86% | moderate |