Contents
- Weather in April
- Frequently asked questions
- Average temperature in April
- Average pressure in April
- Average wind speed in April
- Average humidity in April
- Average rainfall in April
- Average rainfall days in April
- Average snowfall in April
- Average snowfall days in April
- Average daylight in April
- Average sunshine in April
- Average sunshine days in April
- Average UV index in April
- Average cloud cover in April
- Average visibility in April
Weather in April
Temperature
With the transition into April, Mercer Island experiences a subtle uplift in average high-temperatures, adjusting from a cool 50.5°F (10.3°C) in March to a refreshing 55.9°F (13.3°C). During April, the temperature in Mercer Island is averaged to a low of 39.7°F (4.3°C) at night.Humidity
In April, the average relative humidity in Mercer Island, Washington, is 79%.Rainfall
In Mercer Island, in April, it is raining for 12.3 days, with typically 1.06" (27mm) of accumulated precipitation. Throughout the year, there are 119.1 rainfall days, and 11.97" (304mm) of precipitation is accumulated.Snowfall
In Mercer Island, snow does not fall in April through October.Daylight
In April, the average length of the day is 13h and 40min.On the first day of the month, sunrise is at 6:45 am and sunset at 7:39 pm. On the last day of April, in Mercer Island, sunrise is at 5:51 am and sunset at 8:20 pm PDT.
Sunshine
In April, the average sunshine in Mercer Island is 8.1h.UV index
In April, the average daily maximum UV index in Mercer Island is 3. A UV Index of 3 to 5 symbolizes a medium health hazard from unsafe exposure to UV radiation for the ordinary person.Note: The UV index of 3 during April leads to these advisories:
Exercise caution. The susceptibility of light skin individuals to burns is less than 30 minutes. The midday Sun can be dangerous due to its intense radiation; always find shade and reduce exposure. It's wise to wear UVA and UVB-blocking sunglasses when the sun shines brightly. Take heed! The reflection of snow can intensify the Sun's UV radiation nearly double.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average April temperature in Mercer Island?
What is the average humidity in April in Mercer Island?
How many days does it rain in April in Mercer Island?
When it does not snow in Mercer Island?
Does it snow in Mercer Island in April?
How many hours of daylight does Mercer Island have in April?
When are sunrise and sunset in April in Mercer Island?
How long on average sun shines in April in Mercer Island?
How high is the UV index in April in Mercer Island?
Average temperature in April
Mercer Island, WA
- Average high temperature in April: 55.9°F
The warmest month (with the highest average high temperature) is August (76.6°F).
The month with the lowest average high temperature is December (42.8°F).
- Average low temperature in April: 39.7°F
The month with the highest average low temperature is August (53.4°F).
The coldest month (with the lowest average low temperature) is February (34.5°F).
Average pressure in April
Mercer Island, WA
- Average pressure in April: 30.04"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is August (30"Hg).
Average wind speed in April
Mercer Island, WA
- Average wind speed in April: 4.5mph
The windiest month (with the highest average wind speed) is March (5.1mph).
The calmest month (with the lowest average wind speed) is August (3.4mph).
Average humidity in April
Mercer Island, 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
Mercer Island, WA
- Average rainfall in April: 1.06"
The wettest month (with the highest rainfall) is December (2.01").
The driest month (with the least rainfall) is July (0.24").
Average rainfall days in April
Mercer Island, WA
- Average rainfall days in April: 12.3 days
The month with the highest number of rainy days is March (13.7 days).
The month with the least rainy days is August (4.1 days).
Average snowfall in April
Mercer Island, WA
- Average snowfall in April: 0"
The month with the highest snowfall is February (1.77").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in April
Mercer Island, WA
- Average snowfall days in April: 0.1 days
The month with the highest number of snowfall days is February (3 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in April /
Average sunshine in April
Mercer Island, WA
- Average daylight in April: 13h and 4min
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 1min
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 12min).
Average sunshine days in April
Mercer Island, WA
- Average sunshine days in April: 14.8 days
The month with the most sunshine days is August (24.9 days).
The month with the least sunshine days is February (13.8 days).
Average UV index in April
Mercer Island, 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
Mercer Island, WA
- Average cloud cover in April: 50
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
Mercer Island, WA
- Average visibility in April: 5mi
The months with the highest visibility are May, June, July, August and September (6mi).
The months with the lowest visibility are January, February, March, April, October, November and December (5mi).
Mercer Island, Washington, USA
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