Rain, high humidity expected today

By Alli Knothe and Sarah Mattero, Globe Correspondent

It’s a dark day in Boston.

Heavy rain and thunderstorms with high humidity levels and nearly 100 percent cloud cover will persist today as a low pressure system moves through Southern New England, according to the National Weather Service.

The weather service issued a flood warning for parts of Hampden and Hampshire counties and special weather statements saying thunderstorms were rolling through various areas.

Meteorologist Charlie Foley said those areas could see several inches of rain, while the rest of the state will get up to an inch. He said there will be a brief lull in the downpour around noon, but the rain will pick up again between about 1 and 3 p.m.

The weather caused problems for residents of an apartment building in Waltham, who were evacuated because of a lightning strike, fire officials said. Residents received medical evaluation on site but refused treatment.

Waltham Fire Department Lieutenant Mike Murphy said the residents were reportedly “quite shaken” by the event.

The strike hit the roof of the Maple Street building, then traveled down the wall through a power line. The strike blew out an interior wall a third-floor apartment, where three individuals were at the time.

The bolt charred the wood, but there was not much fire, Murphy said. Power to the building was shut off and the owner was on scene with an inspector and an electrician to assess the repairs needed.

It was unknown whether residents would be able to return to the building today.

Though it is not expected to be as heavy as today, the rain and an occasional thunderstorm will likely carry over into Wednesday, forecasters said.

“As we get to the end of the week, there will be gradual improvement,” Foley said.

Temperatures will be in the upper 60s to lower 70s today, the upper 60s Tuesday, and then increase to the mid- to upper 70s Wednesday.

Thursday, Friday, and the weekend will be mostly sunny with a chance of some light rain. Highs will be in the 80s at the end of the week and increase to the 90s on Saturday.

Humidity levels will increase on Friday and continue into the weekend.