April weather forecastSeattle, WA
April
Weather in April
April’s warmer temperatures and lower humidity make it a pleasant time for outdoor activities in Seattle. Temperatures typically begin to show a consistent rise, signaling a move away from the winter chill. The reduction in cloud cover accompanying the change in seasons often creates breathtaking sunrise and sunset views from the city’s many vantage points. Rainfall also tends to decrease, turning the city’s famous drizzle into a rare event. Seattleites eagerly welcome the increased sunshine, a delightful change from the long winter period.Temperature
April brings a slight rise in Seattle's average high-temperature, moving from a cool 50.5°F (10.3°C) in March to a mild 56.5°F (13.6°C). During April, Seattle sees a mean low-temperature of 40.5°F (4.7°C).Humidity
In April, the average relative humidity is 79%.Rainfall
In Seattle, in April, during 8.1 rainfall days, 0.39" (10mm) of precipitation is typically accumulated. In Seattle, during the entire year, the rain falls for 84.2 days and collects up to 5.2" (132mm) of precipitation.Snowfall
April through October and December are months without snowfall.Ocean temperature
In Seattle, the average seawater temperature in April is 45.9°F (7.7°C).Note: Swimming in 45.9°F (7.7°C) poses a severe threat. Even short exposure to 55.4°F (13°C) is chilling, and going below 50°F (10°C) can cause breathing irregularities and intense cold shock, based on one's stamina.
Daylight
In Seattle, Washington, the average length of the day in April is 13h and 41min.On the first day of April in Seattle, sunrise is at 6:45 am and sunset at 7:39 pm. On the last day of the month, sunrise is at 5:52 am and sunset at 8:20 pm PDT.
Sunshine
The average sunshine in April is 8.1h.UV index
The average daily maximum UV index in April is 3. A UV Index value of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV radiation for ordinary individuals.Note: The maximum UV index, 3 during April, leads to the following recommendations:
Be vigilant - Preventing sunburn is recommended. Avoiding direct sunlight during midday hours helps reduce the risk from intense UV radiation. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes. Mind this! Nearly twice the UV radiation from the Sun can be reflected by the snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in April
Seattle, WA
- Average high temperature in April: 56.5°F
The warmest month (with the highest average high temperature) is August (76.3°F).
The month with the lowest average high temperature is December (43.7°F).
- Average low temperature in April: 40.5°F
The month with the highest average low temperature is August (54°F).
The coldest month (with the lowest average low temperature) is December (35.1°F).
Average pressure in April
Seattle, WA
- Average pressure in April: 30.04"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The months with the lowest atmospheric pressure are March, August and September (30.01"Hg).
Average wind speed in April
Seattle, WA
- Average wind speed in April: 4.7mph
The windiest month (with the highest average wind speed) is March (5.3mph).
The calmest months (with the lowest average wind speed) are July and August (3.5mph).
Average humidity in April
Seattle, WA
- Average humidity in April: 79%
The month with the highest relative humidity is January (85%).
The month with the lowest relative humidity is July (69%).
Average rainfall in April
Seattle, WA
- Average rainfall in April: 0.39"
The wettest month (with the highest rainfall) is December (0.87").
The driest months (with the least rainfall) are July and August (0.12").
Average rainfall days in April
Seattle, WA
- Average rainfall days in April: 8.1 days
The month with the highest number of rainy days is November (9.1 days).
The month with the least rainy days is August (2.8 days).
Average snowfall in April
Seattle, WA
- Average snowfall in April: 0"
The month with the highest snowfall is February (0.71").
The months with the least snowfall are April, May, June, July, August, September, October and December (0").
Average snowfall days in April
Seattle, WA
- Average snowfall days in April: 0.1 days
The month with the highest number of snowfall days is February (1.9 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average sea temperature in April
Seattle, WA
- Average sea temperature in April: 45.8°F
The best month for swimming (with the highest average sea temperature) is August (53.5°F).
The coldest month (with the lowest average sea temperature) is February (45.3°F).
Average daylight in April /
Average sunshine in April
Seattle, WA
- Average daylight in April: 13h and 42min
The month with the longest days is June (Average daylight: 15h and 54min).
The month with the shortest days is December (Average daylight: 8h and 30min).
- Average sunshine in April: 8h and 6min
The month with the most sunshine is August (Average sunshine: 10h and 42min).
The month with the least sunshine is December (Average sunshine: 4h and 18min).
Average sunshine days in April
Seattle, WA
- Average sunshine days in April: 18.7 days
The month with the most sunshine days is August (25.9 days).
The month with the least sunshine days is November (16.8 days).
Average UV index in April
Seattle, WA
- Average UV index in April: 3
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in April
Seattle, WA
- Average cloud cover in April: 49
The month with the most cloud cover is December (Cloud cover 56).
The month with the least cloud cover is August (Cloud cover 25).
Average visibility in April
Seattle, WA
- Average visibility in April: 6mi
The months with the highest visibility are April, May, June, July, August, September and October (6mi).
The months with the lowest visibility are January, February, March, November and December (5mi).
