BOSTON — The state’s top elections official estimates that 8 percent to 10 percent of the state’s roughly 4.4 million registered voters will participate in the upcoming state primary election.

Secretary of State William Galvin says he expects turnout on Thursday to be somewhat higher in areas where there are contested races for the Legislature or regional posts such as sheriff or governor’s councilor.

The Democrat says the anticipated low overall turnout reflects the lack of any statewide races on this year’s ballot, and the fact that most incumbent legislators and all nine of the state’s U.S. House representatives are unopposed in the primary.

The election is being held on a Thursday, instead of the usual Tuesday, because of scheduling issues related to the printing of absentee ballots for the November election.