Portland Weather in January

Portland gets a little less total rainfall in January compared with the previous months. But the skies remain cloudy most days, and it rains more often than any other month.

This page gives detailed information on the typical January weather for Portland.

You can jump directly to data and descriptions for:

The numbers here are historical averages based on climate data gathered near the Portland International Airport, located a few miles from downtown Portland.

Temperature Weather iconTemperature

47 °F January average high 8 °C
36 °F January average low 2 °C

In most years, Portland averages a daily maximum temperature for January that's between 44 and 50 degrees Fahrenheit (7 to 10 degrees Celsius). The minimum temperature usually falls between 33 and 38 °F (1 to 4 °C).

The days at Portland begin to warm steadily during January. By the end of the month, the temperature has climbed around 4 °F (2 °C) above what it was at the start.

9 days 50 °F max. or more (10 °C)
8 days 32 °F min. or less (0 °C)

On most days in Portland during January the thermometer makes it over 40 °F (4 °C). On rare days, the temperature has climbed as high as 60 °F (16 °C). Weather as warm as 70 °F (21 °C) is not expected here this month.

Typically on 1 day this month the mercury remains below freezing for the entire day. Most nights, the thermometer dips to 40 °F (4 °C). Although unusual, the temperature can go as low as 20 °F (-8 °C) or below.

Rainy Weather iconPrecipitation

6.1 in total precipitation 154 mm
21 days of rain or snowfall

Half the time, Portland receives 4 to 8 inches (106 to 197 mm) of precipitation in January. One in four years has drier weather, while another one in four is wetter.

Snowy Weather iconSnow

0.9 in total snowfall 2.3 cm
1 day with new snow

Most years, Portland receives no fresh snow during January. In one out of four Januarys, the city gets an inch (3 cm) or more of fresh snow for the month.

Portland has just one or two days in January, on average, when the snow accumulated on the ground amounts to an inch (2.5 cm) or more.

Sunny Weather iconSun

28 % sunshine
3 days clear skies

The sun's rays reach the ground in Portland during 28 percent of daylight hours on average in January, for a total of 80 hours in the month. Typically on 3 days this month the sky is mainly clear, with at most 30 percent cloud cover.

Sunlight in January at Portland lasts for 9 hours and 11 minutes a day on average. The shortest day of the month is the 1st with 8 hours and 47 minutes of daylight. By the end of the month, the days have lengthened to 9:44 from sunrise to sunset. These durations can vary by a minute or two from year to year.

Humid Weather iconHumidity

81 % January average humidity

The relative humidity in Portland during January usually peaks at 85 percent in the morning then drops to 74 percent by mid afternoon.

Local Time1 am4 am7 am10 am1 pm4 pm7 pm10 pm
Humidity % 84 85 85 82 74 74 80 82

Windy Weather iconWind

9.8 mph January wind speed average 15.8 kph

January is the windiest month for Portland.

Stormy Weather iconStorms

5 days rainfall of 0.5 inches (13 mm) or more
0 days with thunderstorms in January

Usually one of Portland's rainstorms drops an inch (25 mm) or more of water in a day on the city. About once a decade, Portland has a January snowstorm that blankets the ground in 3 to 5 inches (8 to 13 cm) of snow.


These weather data are long-term historical averages provided by the National Climatic Data Center of the United States. The temperature and precipitation numbers are 1981-2010 normals while the humidity and thunderstorm statistics are 1961-1990 normals.

Portland Weather
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