Mercer Island (WA) Temperature by Month

This graph shows the average minimum and maximum temperatures throughout the year in Mercer Island (Washington State), the United States of America. The minimum temperature is often recorded between 4 AM and 6 AM, while the highest temperature is usually reached at 3 PM. During this time the sun's heating effect is the strongest.

Temperature patterns do vary with the seasons. In winter, the time of minimum and maximum temperatures can shift slightly compared to summer.

• The months of June, July, August and September have nice average temperatures.
• On average, the warmest month is August with 25°C.
• On average, the coolest month is December with 8°C.
• The average annual maximum temperature is 16°C.
• The average annual minimum temperature is 7°C.