Seattle Weather in March

As spring appoaches, the weather becomes sunnier and temperatures become milder during March at Seattle, Washington.

This page gives detailed information on the typical March temperature, precipitation, sun, humidity, wind and storms for Seattle. The weather measurements are averages based on climate data gathered at Seattle — Tacoma International Airport, located south of the city center.

Temperature Weather iconTemperature

54 °F March average high 12 °C
40 °F March average low 4 °C
23 days 50 °F max. or more (10 °C)
19 days 40 °F min. or less (4 °C)

Usually every day in March the temperature rises to over 40 degrees Fahrenheit (4 degrees Celsius) in Seattle. The city averages 5 days this month when the thermometer reaches into the 60s °F (over 16 °C). Temperatures above 70 °F (21 °C) are unusual during March.

The thermometer dips to freezing on an average of 2 nights. But March does not normally get as cold as 20 °F (-8 °C).

Rainy Weather iconPrecipitation

4.2 in total precipitation 106 mm
17 days of rain

Half the time, Seattle receives 2.8 to 4.8 inches (70 to 121 mm) of rainfall in March. One in four years has drier weather, while another one in four is wetter. Although rare, some of the precipitation this month can fall as snow.

Sunny Weather iconSun

42 % sunshine
4 days clear skies

The sun's rays reach the ground in Seattle during 42 percent of daylight hours on average in March, for a total of 156 hours in the month. Typically on 4 days this month the sky is mainly clear, with at most 30 percent cloud cover.

Sunlight in March at Seattle lasts for 11 hours and 57 minutes a day on average. The shortest day of the month is the 1st with 11 hours and 5 minutes of daylight. By the end of the month, the days have lengthened to 12:49 from sunrise to sunset. These durations can vary by a minute or two from year to year.

Humid Weather iconHumidity

74 % March average humidity

The relative humidity in Seattle during March usually peaks at 83 percent in the morning then drops to 61 percent by late afternoon.

Local Time1 am4 am7 am10 am1 pm4 pm7 pm10 pm
Humidity % 79 82 83 74 64 61 70 75

Windy Weather iconWind

9.4 mph March wind speed average 15.1 kph

March is windier than most other months in Seattle.

Stormy Weather iconStorms

2 days rainfall of 0.5 inches (13 mm) or more
1 day with thunderstorms in March

The weather data here are long-term averages provided by the US National Centers for Environmental Information (NCEI). Temperature and precipitation are 1991-2020 normals while humidity and thunderstorms are 1961-1990 normals.

Seattle Weather
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