Last updated: June 24, 2025
In December, the average temperature in Oregon, United States hovers around -2°C (29°F), but don’t be fooled by the mild average—temperatures can plunge to a brisk -22°C (-8°F), or reach a surprising max of 19°C (66°F). Expect 46 mm (1.8 in) of precipitation over approximately 6 days, with the air maintaining a damp 81% humidity. Bundle up if you're venturing out this month!
In December in Oregon, the average temperature is -2°C (29°F). The maximum can reach 19°C (66°F), and the minimum can be as low as -22°C (-8°F). Be prepared for a wide temperature range and pack accordingly if you're planning to travel during this time.
In Oregon in December, the precipitation amount is 46 mm (1.8 in) over a span of 6 days.
In Oregon in December humidity is 81%. With an average temperature of -2°C (29°F), this humidity feels like an uncomfortable chill that seeps into your bones, making outdoor activities less enjoyable and requiring extra layers to stay warm while traveling.
In Oregon 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 Oregon, you can visit Hourly UV Index in Oregon.
UV Risk Categories
Weather in Oregon varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Oregon, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -6°C (21°F) | 52 mm (2.1 inches) | 85% | moderate |
| February Weather | -5°C (23°F) | 54 mm (2.1 inches) | 85% | moderate |
| March Weather | 2°C (36°F) | 58 mm (2.3 inches) | 85% | moderate |
| April Weather | 8°C (46°F) | 95 mm (3.7 inches) | 85% | very high |
| May Weather | 15°C (60°F) | 133 mm (5.2 inches) | 78% | very high |
| June Weather | 21°C (71°F) | 121 mm (4.8 inches) | 80% | very high |
| July Weather | 24°C (75°F) | 84 mm (3.3 inches) | 78% | very high |
| August Weather | 22°C (71°F) | 111 mm (4.4 inches) | 76% | very high |
| September Weather | 18°C (65°F) | 120 mm (4.7 inches) | 79% | very high |
| October Weather | 11°C (51°F) | 117 mm (4.6 inches) | 83% | moderate |
| November Weather | 2°C (37°F) | 43 mm (1.7 inches) | 88% | moderate |
| December Weather | -2°C (29°F) | 46 mm (1.8 inches) | 81% | low |