Last updated: June 24, 2025
In December, the average temperature in Portland, United States hovers around 2°C (36°F). During this time, you can expect a minimum chill of -16°C (4°F) and a maximum warmth of 17°C (63°F). With 127 mm (5.0 in) of precipitation spread over 10 days, be prepared for some wet weather, complemented by an average humidity of 80%. Embrace the season with a cozy attitude!
In December in Portland, the average temperature is 2°C (36°F). The maximum can reach 17°C (63°F), while the minimum can drop as low as -16°C (4°F). Travelers should be prepared for a wide range of temperatures, making layered clothing essential for comfort during their visit.
In Portland in December, the precipitation amount is 127 mm (5.0 in), spread over a period of 10 days.
In Portland in December humidity is 80%. With an average temperature of 2°C (36°F), this humidity feels like a heavy, damp chill that seeps into your bones, making it challenging for outdoor adventures and often necessitating layered clothing to stay warm and comfortable while exploring.
In Portland 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 Portland, you can visit Hourly UV Index in Portland.
UV Risk Categories
Weather in Portland varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Portland, focusing on differences in temperature, rainfall, humidity, and UV levels.
Temperature | Precipitation | Humidity | UV | |
---|---|---|---|---|
January Weather | 0°C (32°F) | 67 mm (2.6 inches) | 84% | moderate |
February Weather | 1°C (34°F) | 89 mm (3.5 inches) | 82% | moderate |
March Weather | 4°C (40°F) | 90 mm (3.6 inches) | 81% | high |
April Weather | 10°C (49°F) | 126 mm (5.0 inches) | 78% | very high |
May Weather | 15°C (60°F) | 111 mm (4.4 inches) | 69% | very high |
June Weather | 20°C (69°F) | 94 mm (3.7 inches) | 69% | very high |
July Weather | 24°C (75°F) | 156 mm (6.1 inches) | 62% | very high |
August Weather | 23°C (74°F) | 96 mm (3.8 inches) | 65% | very high |
September Weather | 20°C (67°F) | 99 mm (3.9 inches) | 68% | very high |
October Weather | 14°C (58°F) | 130 mm (5.1 inches) | 74% | high |
November Weather | 7°C (44°F) | 90 mm (3.6 inches) | 82% | moderate |
December Weather | 2°C (36°F) | 127 mm (5.0 inches) | 80% | low |