Seattle Weather in April
April is a month of moderate weather for Seattle, Washington. As spring progresses, the city becomes sunnier and drier, yet the temperatures remain mild.
This page gives detailed information on the typical April 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
59 °F | April average high | 15 °C |
43 °F | April average low | 6 °C |
11 days | 60 °F max. or more (16 °C) |
9 days | 40 °F min. or less (4 °C) |
The temperature rises nearly every day during April to over 50 degrees Fahrenheit (10 degrees Celsius) in Seattle. The city averages 2 days this month when the thermometer reaches into the 70s °F (over 21 °C). Temperatures above 80 °F (27 °C) rarely occur here during April.
The thermometer dips to freezing during April only about once a decade .
Rain
3.2 in | total precipitation | 81 mm |
15 days | of rain |
Half the time, Seattle receives 1.9 to 4.3 inches (49 to 108 mm) of rainfall in April. One in four years has drier weather, while another one in four is wetter.
Sun
47 % | sunshine |
5 days | clear skies |
The sun's rays reach the ground in Seattle during 47 percent of daylight hours on average in April, for a total of 193 hours in the month. Typically on 5 days this month the sky is mainly clear, with at most 30 percent cloud cover.
Sunlight in April at Seattle lasts for 13 hours and 40 minutes a day on average. The shortest day of the month is the 1st with 12 hours and 52 minutes of daylight. By the end of the month, the days have lengthened to 14:27 from sunrise to sunset. These durations can vary by a minute or two from year to year.
Humidity
71 % | April average humidity |
The relative humidity in Seattle during April usually peaks at 83 percent in the morning then drops to 57 percent by late afternoon.
Local Time | 1 am | 4 am | 7 am | 10 am | 1 pm | 4 pm | 7 pm | 10 pm |
Humidity % | 79 | 83 | 82 | 71 | 60 | 57 | 65 | 74 |
Wind
9.3 mph | April wind speed average | 15.0 kph |
April is windier than most other months in Seattle.
Storms
2 days | rainfall of 0.5 inches (13 mm) or more |
1 day | with thunderstorms in April |
April is one of the months when Seattle is most likely to have a thunderstorm. Still, thunder and lightning don't happen here every year during April.
Reference
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.