Last updated: June 24, 2025
In December, the average temperature in Mountain View, United States hovers around -5°C (23°F), with a notable range that can dip to a chilly -24°C (-10°F) and peak at a mild 14°C (58°F). Expect 31 mm (1.2 in) of precipitation spread over 8 days, contributing to an average humidity level of 88%—perfect for cozy indoor activities!
In December in Mountain View, the average temperature is -5°C (23°F). The maximum can reach 14°C (58°F), while the minimum can drop as low as -24°C (-10°F). It's essential to pack warm clothing and be prepared for a wide range of temperatures when traveling during this month.
In Mountain View in December, the precipitation amount is 31 mm (1.2 in) over the course of 8 days.
In Mountain View in December humidity is 88%. With an average temperature of -5°C (23°F), this humidity feels like an icy blanket enveloping you, making travel uncomfortable as the cold damp air seeps through layers of clothing, chilling you to the bone.
In Mountain View 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 View, you can check the information here.
UV Risk Categories
Weather in Mountain View varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Mountain View, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -6°C (22°F) | 30 mm (1.2 inches) | 91% | moderate |
| February Weather | -5°C (24°F) | 34 mm (1.3 inches) | 92% | high |
| March Weather | -1°C (31°F) | 67 mm (2.6 inches) | 84% | very high |
| April Weather | 4°C (39°F) | 50 mm (2.0 inches) | 74% | very high |
| May Weather | 9°C (49°F) | 67 mm (2.7 inches) | 62% | extreme |
| June Weather | 17°C (62°F) | 24 mm (0.9 inches) | 56% | extreme |
| July Weather | 21°C (70°F) | 15 mm (0.6 inches) | 44% | extreme |
| August Weather | 19°C (67°F) | 24 mm (0.9 inches) | 37% | extreme |
| September Weather | 14°C (58°F) | 29 mm (1.2 inches) | 46% | very high |
| October Weather | 5°C (42°F) | 30 mm (1.2 inches) | 67% | high |
| November Weather | 1°C (34°F) | 32 mm (1.2 inches) | 84% | moderate |
| December Weather | -5°C (23°F) | 31 mm (1.2 inches) | 88% | moderate |