Posted in Web Mercer Island, WA Weather – The Weather Channel October 9, 2024 Be prepared with the most accurate 10-day forecast for Mercer Island, WA with highs, lows, chance of precipitation from The Weather Channel and Weather.com https://weather.com/weather/tenday/l/Mercer+Island+WA?canonicalCityId=c854c863d5011e4907e4e26f5fea5c8849e4c878068961a4eb82f9b65c28befe