Rock Island is located in Washington. Rock Island, Washington has a population of 1,158. Rock Island is less family-centric than the surrounding county with 23% households with children. The county percentage for households with children is 31%.
The median household income in Rock Island, Washington is $56,840. The median household income for the surrounding county is $66,354 compared to the national median of $66,222. The median age of people living in Rock Island is 38 years.
The average high temperature in July is 86.7 degrees, with an average low temperature in January of 21.8 degrees. The annual precipitation is 8.51.