Last updated: June 24, 2025
In December, the average temperature in Corvallis, United States hovers around 5°C (41°F). While you might experience a crisp chill with a minimum of -6°C (21°F), the mercury can peak at a mild 17°C (63°F). Expect 189 mm (7.4 in) of rain spread across 17 days, accompanied by average humidity levels of 87%, creating a refreshing atmosphere throughout the month.
In December in Corvallis, the average temperature is 5°C (41°F), with maximums reaching 17°C (63°F) and minimums dropping as low as -6°C (21°F). Be sure to pack accordingly for varied weather conditions during your travels.
In Corvallis in December, the total precipitation amount is 189 mm (7.4 in) over a span of 17 days.
In Corvallis in December humidity is 87%. With an average temperature of 5°C (41°F), this humidity feels like a heavy, damp blanket enveloping you, making every step seem laborious and the chill more biting, which can be quite challenging for traveling.
In Corvallis 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 Corvallis, you can visit Hourly UV Index in Corvallis.
UV Risk Categories
Weather in Corvallis varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Corvallis, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | 5°C (42°F) | 155 mm (6.1 inches) | 85% | low |
| February Weather | 5°C (41°F) | 179 mm (7.0 inches) | 84% | moderate |
| March Weather | 7°C (45°F) | 133 mm (5.2 inches) | 85% | high |
| April Weather | 10°C (50°F) | 117 mm (4.6 inches) | 83% | high |
| May Weather | 13°C (57°F) | 60 mm (2.3 inches) | 83% | very high |
| June Weather | 17°C (63°F) | 42 mm (1.7 inches) | 83% | very high |
| July Weather | 20°C (69°F) | 3 mm (0.1 inches) | 82% | very high |
| August Weather | 21°C (69°F) | 5 mm (0.2 inches) | 74% | very high |
| September Weather | 17°C (64°F) | 61 mm (2.4 inches) | 71% | very high |
| October Weather | 12°C (53°F) | 84 mm (3.3 inches) | 81% | moderate |
| November Weather | 8°C (46°F) | 139 mm (5.5 inches) | 87% | moderate |
| December Weather | 5°C (41°F) | 189 mm (7.4 inches) | 87% | low |