Just in time for the weather to warm up, super PACs backing Boston Mayor Michelle Wu and main challenger Josh Kraft are turning up the heat in the race for City Hall.
All told, independent expenditure groups on either side of the already tense mayoral campaign recently have poured nearly $1 million into the contest, state records show.
The pro-Wu super PAC Bold Boston reported raising $743,000 between Jan. 1 and June 12, according to a report filed with the state’s Office of Campaign and Political Finance. The group reported spending $256,114…