About Sumner, WASumner is located in Washington. Sumner, Washington has a population of 10,248. Sumner is more family-centric than the surrounding county with 32% households with children. The county percentage for households with children is 31%. The median household income in Sumner, Washington is $52,560. The median household income for the surrounding county is $55,937 compared to the national median of $50,013. The median age of people living in Sumner is 39.8 years. Sumner WeatherThe average high temperature in July is 74.5 degrees, with an average low temperature in January of 31.7 degrees. The annual precipitation is 43.12. Real estate near SumnerNearby Cities |