 Sedro-Woolley has a warm-summer Mediterranean climate (Csb) according to the Köppen climate classification system, but nearly qualifies as having an Oceanic climate (Cfb) due to its less pronounced drying trend in summer, as compared with elsewhere in western Washington.As of the census of 2010, there were 10,540 people, 3,995 households, and 2,609 families residing in the city.The population density was .