Last updated: June 24, 2025
In December, the average temperature in Mountain House, United States hovers around 9°C (49°F), with a minimum dipping as low as -2°C (29°F) and a maximum reaching up to 22°C (71°F). Expect 78 mm (3.1 in) of precipitation over 9 days, coupled with a high average humidity of 80%. Prepare accordingly for this mix of cool temperatures and moist conditions!
In December in Mountain House, the average temperature is 9°C (49°F). Maximums can reach 22°C (71°F) and minimums can be as low as -2°C (29°F). Travelers should be prepared for a range of temperatures and pack accordingly to enjoy their visit to Mountain House.
In Mountain House in December, the precipitation amount is 78 mm (3.1 in) over the course of 9 days.
In Mountain House in December, humidity is 80%. With an average temperature of 9°C (49°F), this humidity feels like a damp chill that seeps into your bones, making outdoor activities less enjoyable and prompting a need for layered clothing to stay comfortable while traveling.
In Mountain House 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 Mountain House, you can check the information here.
UV Risk Categories
Weather in Mountain House varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Mountain House, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | 10°C (50°F) | 92 mm (3.6 inches) | 82% | moderate |
| February Weather | 11°C (52°F) | 76 mm (3.0 inches) | 84% | moderate |
| March Weather | 12°C (55°F) | 75 mm (2.9 inches) | 82% | very high |
| April Weather | 16°C (60°F) | 31 mm (1.2 inches) | 78% | very high |
| May Weather | 19°C (66°F) | 16 mm (0.6 inches) | 71% | extreme |
| June Weather | 22°C (73°F) | 1 mm (0.0 inches) | 64% | extreme |
| July Weather | 24°C (75°F) | 0 mm (0.0 inches) | 58% | extreme |
| August Weather | 24°C (75°F) | 0 mm (0.0 inches) | 54% | very high |
| September Weather | 22°C (71°F) | 2 mm (0.1 inches) | 55% | very high |
| October Weather | 18°C (64°F) | 22 mm (0.9 inches) | 62% | high |
| November Weather | 13°C (55°F) | 33 mm (1.3 inches) | 78% | moderate |
| December Weather | 9°C (49°F) | 78 mm (3.1 inches) | 80% | moderate |