Average Monthly Sunshine in Mercer Island (WA)

The graphs on this page shows the average number of hours per month and per day that Mercer Island receives direct sunlight. The numbers are calculated over a 30-year period to provide a reliable average.

Monthly hours of sunshine

Seasonal sunshine in Mercer Island varies. It peaks at 312 hours in July and drops to 54 hours in December. The total annual amount of sun is 2180 hours.

Daily hours of sunshine

Seasonal changes in sunshine hours are quite obvious in Mercer Island. While July receives considerable daily sunshine with up to 10.4 hours, December marks the darkest time of the year, where sunshine is scarce with only 1.8 hours of sunlight per day.

Mercer Island’s total hours of sunshine compared to other major cities

Mercer Island enjoys an average of 2180 hours of sunshine annually. Let’s compare this with some popular tourist destinations:

Athens, Greece, enjoys 2769 hours of sunshine each year, making it one of the sunniest destinations in the Mediterranean region.

The climate in San Francisco, USA, includes 3072 hours of sunshine annually, thanks to its mild coastal weather.

Stockholm, Sweden, receives approximately 1907 hours of sunshine annually.

Adelaide, Australia, enjoys 2770 hours of sunshine annually, with long, sunny summers.

Other climate information

November, Mercer Island’s wettest month, receives 25 mm of rainfall and has a maximum daytime temperature of 11°C. During the driest month July you can expect a temperature of 25°C.

For more detailed insights into the city’s temperatures, check out our Temperature page. To explore more about precipitation patterns, visit our Mercer Island Precipitation page.