Nearly 23 percent of registered voters cast their ballot in Tuesday's primary, exceeding election officials' forecasts.
A total of 392,142 Kansans cast ballots, about 22.8 percent of all registered voters.
Kris Kobach, Kansas Secretary of State, had predicted 18 percent voter turnout last week.
“It is nevertheless good news that Kansas voters turned out in higher numbers than we estimated,” Kobach said.
Kobach credited the heavily contested Senate races across the state for the higher number of ballots cast. Participation rates varied widely from county to county and from district to district.
The county with the highest turnout was Greeley County with 64.7 percent. The lowest participation was in Wyandotte County with 11.3 percent.
More than 20 percent of registered voters in Sedgwick County participated in the election.