January Weather in Portland, United States

Last updated: June 24, 2025

In January, the average temperature in Portland, United States hovers around -7°C (20°F). It can dip as low as -33°C (-27°F) and peak at a mild 9°C (49°F). Expect around 38 mm (1.5 in) of precipitation spread over 8 days, and with an average humidity of 84%, be prepared for chillier conditions!

January Temperature in Portland

In January, in Portland, the average temperature is -7°C (20°F). Maximums can reach 9°C (49°F), while minimums can dip as low as -33°C (-27°F). Travelers should be prepared for chilly weather, bringing appropriate clothing to ensure comfort during their visit.

January Weather in Portland: Daily Temperature Highs, Lows, and Averages

The chart illustrates January temperature patterns in Portland, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Portland, January typically has an average temperature of -7°C (20°F), with highs reaching up to 9°C (49°F) and lows dropping to around -33°C (-27°F).

Data source: Temperature data for Portland generated using information from the Copernicus Climate Change Service.

January Precipitation in Portland

In Portland in January, the total precipitation amount is 38 mm (1.5 in), spread over 8 days.

January Precipitation Trends in Portland

The chart displays monthly precipitation patterns in Portland, with values for each month alongside January’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how January’s conditions compare to those of other months. In Portland, January typically receives around 38 mm (1.5 inches) of precipitation spread over approximately 8 days.

Data source: Precipitation data for January generated using information from the Copernicus Climate Change Service.

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Millimeters (mm) Inches (in)

January Humidity in Portland

In Portland in January, humidity is 84%. With an average temperature of -7°C (20°F), this humidity feels like a damp chill that seeps into your bones, making traveling uncomfortable and requiring extra layers to stay warm and dry.

January Average Humidity in Portland

This chart illustrates the average monthly humidity levels in Portland, with January’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In January, average humidity in Portland is approximately 84%, offering insight into how humid the weather typically is during this month.

Data source: Humidity data for January generated using information from the Copernicus Climate Change Service.

January UV Index in Portland

In Portland in January, 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.

Maximum UV Index Levels in Portland for January

The chart shows the monthly maximum UV Index (UVI) for Portland in January, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In January, the maximum UV index in Portland typically reaches 2, which falls under the low exposure category.

Data source: Portland January UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

Extreme (11+): Avoid the sun, stay in shade.
Very High (8-10): Limit sun exposure.
High (6-7): Use SPF 30+ and protective clothing.
Moderate (3-5): Midday shade recommended.
Low (0-2): No protection needed.

How January Weather in Portland Compares to Other Months

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.

This table compares monthly weather conditions in Portland, showing how January’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-7°C (20°F)	38 mm (1.5 inches)	84%	low
February Weather	-6°C (21°F)	54 mm (2.1 inches)	85%	moderate
March Weather	2°C (35°F)	60 mm (2.3 inches)	84%	moderate
April Weather	7°C (45°F)	92 mm (3.6 inches)	83%	very high
May Weather	15°C (59°F)	139 mm (5.5 inches)	75%	very high
June Weather	21°C (70°F)	124 mm (4.9 inches)	79%	very high
July Weather	23°C (74°F)	112 mm (4.4 inches)	75%	very high
August Weather	21°C (70°F)	112 mm (4.4 inches)	69%	very high
September Weather	18°C (64°F)	111 mm (4.4 inches)	74%	very high
October Weather	10°C (50°F)	119 mm (4.7 inches)	79%	moderate
November Weather	1°C (35°F)	53 mm (2.1 inches)	88%	moderate
December Weather	-3°C (27°F)	44 mm (1.7 inches)	82%	low