Portland Weather in October

Portland, Oregon sees a shift during October from summer's dry, sunny weather to winter's wet, cloudy climate.

This page gives detailed information on the typical October temperature, precipitation, sun, humidity, wind and storms for Portland. The numbers here are historical averages based on climate data gathered near the Portland International Airport, located a few miles from downtown Portland.

Temperature

64 °F	October average high	18 °C
46 °F	October average low	8 °C

22 days	60 °F max. or more (16 °C)
23 days	50 °F min. or less (10 °C)

Usually every October day warms to over 50 degrees Fahrenheit (10 degrees Celsius) in Portland. The city averages 6 days this month when the thermometer reaches into the 70s °F (over 21 °C). October averages one day of temperatures above 80 °F (27 °C).

The thermometer typically drops to 40 °F (4 °C) or below on 5 nights in the month. Frost in October occurs about twice a decade.

Rain

4.0 in	total precipitation	101 mm
15 days	of rain

Half the time, Portland receives 2.6 to 5.0 inches (66 to 128 mm) of rainfall in October. One in four years has drier weather, while another one in four is wetter. None of the precipitation falls as snow this month.

Sun

44 %	sunshine
5 days	clear skies

The sun's rays reach the ground in Portland during 44 percent of daylight hours on average in October, for a total of 149 hours in the month. Typically on 5 days this month the sky is mainly clear, with at most 30 percent cloud cover.

Sunlight in October at Portland lasts for 10 hours and 54 minutes a day on average. The longest day of the month is the 1st with 11 hours and 41 minutes of daylight. By the end of the month, the days have shortened to 10:09 from sunrise to sunset. These durations can vary by a minute or two from year to year.

Humidity

78 %	October average humidity

The relative humidity in Portland during October usually peaks at 90 percent in the morning then drops to 60 percent by mid afternoon.

Local Time	1 am	4 am	7 am	10 am	1 pm	4 pm	7 pm	10 pm
Humidity %	87	90	90	78	63	60	74	82

Wind

6.5 mph

October wind speed average

10.5 kph

October is one of the least windy months in Portland.

Storms

3 days	rainfall of 0.5 inches (13 mm) or more
0 days	with thunderstorms in October

Some years, Portland gets an inch (25 mm) or more of rain in one day during October. Every few years a thunderstorm shows up at Portland during this month.