Last updated: June 24, 2025
In January, the average temperature in Portland, United States hovers around -1°C (31°F). You'll experience a range of temperatures, with a minimum dipping to -19°C (-3°F) and a maximum peaking at 17°C (63°F). Expect some moisture, as precipitation averages 71 mm (2.8 in) spread over 8 days. With an average humidity of 87%, it's a month that demands a cozy wardrobe!
In January in Portland, the average temperature is -1°C (31°F). Maximum temperatures can reach 17°C (63°F), while minimums can drop as low as -19°C (-3°F). Travelers should be prepared for a wide range of temperatures and pack accordingly for their visit to Portland.
In Portland in January, the precipitation amount is 71 mm (2.8 in) over the course of 8 days.
In Portland in January humidity is 87%. With an average temperature of -1°C (31°F), this humidity feels like a biting chill that seeps through your clothes, making traveling incredibly uncomfortable as it adds a layer of dampness to the already cold air, leaving you shivering and wishing for warmth.
In Portland in January, 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 Portland, you can check the information here.
UV Risk Categories
Weather in Portland varies notably across the year, with each month offering distinct climate conditions. This page compares January’s weather to other months in Portland, focusing on differences in temperature, rainfall, humidity, and UV levels.
Temperature | Precipitation | Humidity | UV | |
---|---|---|---|---|
January Weather | -1°C (31°F) | 71 mm (2.8 inches) | 87% | moderate |
February Weather | 1°C (34°F) | 102 mm (4.0 inches) | 85% | moderate |
March Weather | 4°C (39°F) | 94 mm (3.7 inches) | 85% | high |
April Weather | 10°C (50°F) | 110 mm (4.3 inches) | 83% | very high |
May Weather | 16°C (61°F) | 135 mm (5.3 inches) | 75% | very high |
June Weather | 21°C (69°F) | 92 mm (3.6 inches) | 73% | very high |
July Weather | 24°C (75°F) | 124 mm (4.9 inches) | 65% | very high |
August Weather | 23°C (73°F) | 125 mm (4.9 inches) | 62% | very high |
September Weather | 19°C (67°F) | 107 mm (4.2 inches) | 66% | very high |
October Weather | 14°C (57°F) | 141 mm (5.5 inches) | 79% | high |
November Weather | 6°C (42°F) | 90 mm (3.5 inches) | 87% | moderate |
December Weather | 2°C (35°F) | 106 mm (4.2 inches) | 85% | low |