Last updated: June 24, 2025
In December, the average temperature in San Rafael, United States hovers around 10°C (51°F), with extremes ranging from a brisk 3°C (38°F) to a warm 22°C (72°F). Be prepared for some rain, as you can expect about 98 mm (3.9 in) of precipitation over approximately 9 days. With an average humidity of 79%, it's a month that combines cool breezes with the potential for soggy days—perfect for cozy indoor activities!
In December in San Rafael, the average temperature is 10°C (51°F). Maximums can reach 22°C (72°F) and minimums can be as low as 3°C (38°F). It's a great time for travelers to enjoy mild weather while exploring the sights and sounds of San Rafael.
In San Rafael in December, the precipitation amount is 98 mm (3.9 in) spread over a duration of 9 days.
In San Rafael in December, humidity is 79%. With an average temperature of 10°C (51°F), this humidity feels like a damp chill that seeps into your bones, making outdoor activities less enjoyable and travel somewhat uncomfortable unless you're properly layered.
In San Rafael 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 San Rafael, you can check the information here.
UV Risk Categories
Weather in San Rafael varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in San Rafael, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | 10°C (51°F) | 111 mm (4.4 inches) | 85% | moderate |
| February Weather | 11°C (52°F) | 116 mm (4.6 inches) | 82% | moderate |
| March Weather | 12°C (54°F) | 80 mm (3.1 inches) | 82% | very high |
| April Weather | 14°C (57°F) | 35 mm (1.4 inches) | 79% | very high |
| May Weather | 15°C (60°F) | 20 mm (0.8 inches) | 83% | very high |
| June Weather | 17°C (63°F) | 2 mm (0.1 inches) | 84% | extreme |
| July Weather | 17°C (63°F) | 2 mm (0.1 inches) | 87% | extreme |
| August Weather | 18°C (64°F) | 1 mm (0.1 inches) | 87% | very high |
| September Weather | 18°C (65°F) | 2 mm (0.1 inches) | 86% | very high |
| October Weather | 16°C (62°F) | 30 mm (1.2 inches) | 80% | high |
| November Weather | 13°C (55°F) | 48 mm (1.9 inches) | 79% | moderate |
| December Weather | 10°C (51°F) | 98 mm (3.9 inches) | 79% | moderate |