Mercer Island Weather in August

During August, Mercer Island experiences high daytime temperatures of 25°C (77°F) and cooler nights around 14°C (57°F). As part of the summer season, some rainfall is to be expected.

Rainfall in Mercer Island in August

This month experiences about 5 days of rain according to historical data, averaging 25 mm (1 in). Rain days are few and the total is low, so this is a largely dry month. Any showers that do occur tend to be brief.

Temperature in Mercer Island in August

If you're visiting Mercer Island in August, expect perfect temperatures with highs of 25°C (77°F) and overnight lows of 14°C (57°F). This month falls in the summer season. The days can feel warmer than the evenings, so packing for both parts of the day is a good idea. At 14°C (57°F) overnight, it can feel quite a bit cooler after dark. Worth packing something warmer for evenings, but the cooler temperatures are ideal for sleeping. This month tends to be the warmest of the year. Light, comfortable clothing will serve you well.

Sunshine in Mercer Island in August

The days are predominantly sunny, with an estimated total of around 280 hours of sunshine. These sun-filled days are perfect for playing sports, visiting parks, or going for a bike ride.

Wind Speed in Mercer Island in August

In August, average wind speeds reach 4 m/s (8 knots), leading to light to moderate breezes. Conditions vary from day to day, with both calm and windier periods.

If your ideal day consists of dry skies and pleasant temperatures, June, July, August and September typically offer the best circumstances for Mercer Island.

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For a detailed overview over the year and the best time to visit the United States of America, check out our Mercer Island's climate page.

Mercer Island Temperature in August

Min Temperature 14°C (57°F)  

Max Temperature 25°C (77°F)  

Chance of Rain 17%  

Precipitation 25 mm (1 in)  

Rainy days 5 days  

Humidity 68% *  

Windspeed 4 m/s (8 knots) *  

Sunshine 280 hours *  

Percentage Sunshine 64% *  

* Data from: Seattle, the United States of America (15 KM, 9 Miles).

What to Wear in Mercer Island in August

Warm but pleasant conditions in Mercer Island in August. Focus on lightweight, maybe with natural fabrics, cotton blend shirts, comfortable shorts, and breathable footwear. A light cover-up for sun protection is smart too. Light rain is possible, so consider bringing a small umbrella or rain jacket. And with plenty of sunshine hours, don’t forget sunglasses, sunscreen, and maybe a sun hat.

What To Do in Mercer Island in August

We rated the following activities from 1 (least suitable) to 10 (best) to do.

Swimming

10/10

Cycling

8/10

Walking

8/10

Barbeque

10/10

Camping

10/10

Outdoor sports

8/10

Select a Month

Check the conditions for any month of the year.

• January
• February
• March
• April

• May
• June
• July
• August

• September
• October
• November
• December

For a detailed overview over the year and the best time to visit the United States of America, check out our Mercer Island's climate page.

More climate data for Mercer Island

Temperature Rainfall Sunshine Humidity Wind Speed

See the full Mercer Island climate overview or explore weather in the United States of America.