The National Weather Service has issued a freeze watch for just about all the suburbs away from and along the coast Friday night into Saturday morning.
State health officials urge people to take precautions to keep from being bitten by mosquitoes.
State public health officials say two more human cases of mosquito-borne West Nile virus have been confirmed in Massachusetts.
According to the Boston Public Health Commission, a positive pool of mosquitoes was found in North Dorchester and another was found in Hyde Park for the first time this season.
Public health officials say the virus that causes Eastern equine encephalitis has been found in mosquitoes collected in Bolton.
Breezy conditions have prompted the cancellation of the aerial mosquito spraying scheduled to happen Wednesday night in southeastern Massachusetts.