South Prairie is a city located in Washington. With a 2020 population of 441, it is the 245th largest city in Washington and the 13855th largest city in the United States. South Prairie is currently declining at a rate of -0.23% annually but its population has increased by 1.61% since the most recent census, which recorded a population of 434 in 2010. South Prairie reached it's highest population of 444 in 2018. Spanning over 0 miles, South Prairie has a population density of 1,151 people per square mile.
The average household income in South Prairie is $89,864 with a poverty rate of 14.20%. The median rental costs in recent years comes to $1,250 per month, and the median house value is $244,700. The median age in South Prairie is 49.7 years, 53 years for males, and 41 years for females. For every 100 females there are 101.9 males.