Mercer Island weather
At 5:30 PM local time it was partly cloudy and 9°C (48°F). Little to no rain in the next 24 hours. Best months for weather: May–Sep. Mercer Island sits 103 m (338 ft) above sea level, which keeps it cooler than the coast. Below: today's sky, the hour-by-hour rain chance and the 16-day forecast for Mercer Island, Washington, United States.
Current conditions
- Clouds
- 61%
- Chance of rain
- 0%
- Rain
- 0.0 mm/h
Hourly Forecast
Little to no rain in the next 24 hours
Daily Forecast
Best Time to Visit
Peak season May–SepOff season Nov–Mar
About Mercer Island weather
Is it raining in Mercer Island right now?
No. It’s partly cloudy and 9° right now. Little to no rain in the next 24 hours.
What’s the weather like in Mercer Island this week?
Over the next 7 days, expect highs of 11–14° and lows of 1–10°. Rain is likely on 1 of 7 days (Friday). The driest day looks like Monday.
Has it been raining in Mercer Island lately?
In the past 7 days, Mercer Island had 4 rainy days and 12.3 mm of rain in total.
What should I pack for Mercer Island?
For the coming week, bring an umbrella or rain jacket and a warm winter coat.
Mercer Island weather by month
When is the best time to visit Mercer Island?
Based on weather alone, the best time to visit Mercer Island is May–Sep, according to NASA's 2001–2025 climate averages. Nov–Mar tends to be the least pleasant. Average highs run from 6°C (44°F) in December to 23°C (74°F) in August.
What is the rainiest month in Mercer Island?
November is the wettest month, with about 188 mm (7.4 in) of rain on average. July is the driest, with about 19 mm (0.7 in).
What is the hottest month in Mercer Island?
August is the warmest, with average highs of 23°C (74°F) and lows of 13°C (56°F). December is the coolest, with highs of 6°C (44°F) and lows of 1°C (34°F).
Does Mercer Island have a rainy season?
Yes. Nov–Jan is the rainy season (150 mm or more a month), while Jun–Sep is usually dry (under 60 mm).
Sources: 2001–2025 monthly averages from NASA POWER (MERRA-2 reanalysis), forecast and current conditions from Open-Meteo. Page updated . How we rate months