temperature in renton
Average Weather in Renton Washington, United States. Renton has a mediterranean climate with dry warm summers and mild winters. The temperature typically varies from 37Â°F to 79Â°F over the course of the year, and is rarely below 27Â°F or above 89Â°F. The warm season lasts for 85 days, from June 21 to September 14, with an average daily high temperature above 72Â°F.