Mercer Island, WA weather
Today, hourly and 7-day forecast, sunrise and sunset, and the normal climate month by month
Weather in Mercer Island now
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Mercer Island weather by the hour
Mercer Island weather for the next 7 days
Source: National Weather Service (NOAA) · forecast for the coordinates of Mercer Island.
This week in Mercer Island
Sunrise, sunset and moon in Mercer Island
What is the weather usually like in Mercer Island?
Köppen climate classification, calculated from the 1991–2020 normals
- Julywarmest month · 77°F average high
- Decembercoldest month · 36°F average low
- 36.5 inprecipitation per year · 927 mm
Average high and low temperature (°F)
Average precipitation (inches)
Best time to visit Mercer Island: June to September, with mild temperatures and fewer rainy days.
Source: NOAA NCEI U.S. Climate Normals 1991–2020, station SEATTLE BOEING FLD, WA US (USW00024234), adjusted for the elevation of Mercer Island.
Mercer Island weather month by month
Sunrise and sunset in Mercer Island through the year
| Month | Sunrise | Sunset | Daylight |
|---|---|---|---|
| January | 7:50 AM | 4:46 PM | 8 h 56 min |
| February | 7:12 AM | 5:33 PM | 10 h 21 min |
| March | 7:19 AM | 7:16 PM | 11 h 56 min |
| April | 6:17 AM | 8:00 PM | 13 h 42 min |
| May | 5:29 AM | 8:41 PM | 15 h 12 min |
| June | 5:08 AM | 9:10 PM | 16 h 1 min |
| July | 5:25 AM | 9:04 PM | 15 h 38 min |
| August | 6:03 AM | 8:22 PM | 14 h 19 min |
| September | 6:45 AM | 7:22 PM | 12 h 37 min |
| October | 7:26 AM | 6:22 PM | 10 h 55 min |
| November | 7:12 AM | 4:34 PM | 9 h 21 min |
| December | 7:48 AM | 4:19 PM | 8 h 31 min |
Times for the 15th of each month, local time (America/Los Angeles).
What is the weather like in Mercer Island?
Mercer Island has a warm-summer mediterranean climate. The warmest month is July, with an average high of 77°F (25°C), and the coldest is December, with average lows of 36°F (2°C).
It gets about 36.5 inches (927 mm) of precipitation a year. The wettest month is November and the driest is July.
The best time to visit Mercer Island is June to September. The live forecast on this page comes from the National Weather Service and the climate averages from NOAA’s 1991–2020 U.S. Climate Normals.
More about Mercer Island
Weather in towns near Mercer Island
Questions about the weather in Mercer Island
What is the hottest month in Mercer Island?
July, with an average high of 77°F (25°C).
What is the coldest month in Mercer Island?
December, with an average low of 36°F (2°C).
How much does it rain in Mercer Island?
About 36.5 inches (927 mm) a year; the wettest month is November.
Does it snow in Mercer Island?
Snow is very rare or not recorded at the nearest weather station.
When is the best time to visit Mercer Island?
June to September, when temperatures are most pleasant and rainy days are fewer.
What climate does Mercer Island have?
Warm-summer mediterranean (Köppen Csb).
What is the weather like in Mercer Island in November?
Highs average 53°F and lows 40°F, with about 5.8 inches of precipitation.
What time is sunrise in Mercer Island?
Around 7:12 AM in mid-November, and sunset around 4:34 PM. Today’s exact times are shown above.
Where does this Mercer Island weather forecast come from?
From the National Weather Service (NOAA), the official U.S. weather agency, for the exact coordinates of Mercer Island.
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