Additional voting sites are opening across Cook County and the rest of the state for voters who want to cast an early ballot for the primary March 20.

Some early voting locations in Chicago opened last month, but many more are set to open Monday, offering voting during mornings, evenings and weekends in addition to regular business hours.

Voters will choose the Democratic and Republican nominees for governor, attorney general and many other contested races, along with local races such as the Cook County Board of Commissioners.

RELATED: Check out the Sun-Times 2018 Illinois Primary Voting Guide

Illinois has an open primary, meaning voters don’t have to belong to a particular party or declare a formal affiliation to cast a ballot in either the Republican or Democratic contests. Voters don’t have to provide a reason why they can’t vote on March 20.

What you need to know: