His ruling capped a week of high political drama in Arkansas, one of a number of states — including Florida, South Carolina and Texas — where conservative elected officials have prohibited mask mandates despite spikes in new cases driven by the highly contagious Delta variant.
The Arkansas law prohibits most government entities in the state from requiring masks. Mr. Hutchinson has said he regretted his decision to sign it, and convened a special session of the Republican-controlled legislature that began on Wednesday, asking lawmakers to change the law so that school districts could issue mask mandates.
The legislators declined to take action before ending the session on Friday morning.
Tom Mars, the lawyer who brought the lawsuit against the law on behalf of parents in the Little Rock school district, said that the judge’s ruling freed up Arkansas school districts and other government entities to issue mask mandates for the foreseeable future. Mr. Mars said it was not clear when the court might take up his request that the law be permanently blocked.
School districts in Little Rock and Marion, Ark., have filed a separate lawsuit challenging the ban.
On Thursday, Little Rock’s mayor, Frank Scott Jr., announced a mask mandate in public places, joining a wave of other local government and school officials in Texas and Florida defying state bans.