It’s safe to go out after dark again.
The National Weather Service announced that most areas of Massachusetts, including the Newburyport region, experienced a hard freeze on Friday night, killing all the mosquitoes and effectively ending this year’s threat of mosquito-borne illness.
Local communities had been on high alert after two local residents contracted Eastern equine encephalitis last month, one in Georgetown and the other in Amesbury. Both residents later died.
As a result, both communities’ EEE threat levels were raised to the highest alert level — critical — along with Haverhill and Merrimac. All other local communities’ threat levels were raised to high, which is the second highest threat level on the five-level scale. In response, most communities in the area instituted overnight bans on public spaces to protect residents against mosquitoes during their most active periods.
With the end to the threat, those bans are now being lifted. Officials in Amesbury, Newbury, Georgetown, Salisbury, West Newbury and Merrimac said that they will be rescinding the overnight bans, which had been in place since mid-September and restricted any town events on public spaces.
Newburyport has not lifted the ban yet, because the Board of Health does not think that a killing frost has occurred in the city. The city's health inspector, Bob Bracey, has recommended that the city end the outdoor ban based on the National Weather Service's report of the widespread frost last week.
The biggest impact the ban had was on local high school sports. Hundreds of games and practices had to be rescheduled over the past few weeks, including all night games. Many teams even saw shotgun start times for games after school in order to squeeze the game in before the ban, some starting as early as 2:30 p.m.
The end to the threat is a relief to officials and residents, who had to wait over the weekend for the state to determine whether Friday’s frost was cold enough.
“I was getting a lot of questions from folks anxiously awaiting the results of the frost,” said Amesbury Mayor Thatcher Kezer. “The first reports we got was that it wasn’t enough of a frost, but then we got another more detailed report which indicated that this part of the state had a sufficient frost and other parts didn’t, so it was that additional information that clarified that it was a sufficient killer frost.”
The NWS defines a hard freeze as temperatures falling below 28 degrees at any point or falling below 32 degrees for three hours or longer. By this definition, all of Massachusetts experienced a hard freeze except Suffolk County, the Cape and the islands in Nantucket Sound.
The NWS said that while individual mosquitoes may have survived in isolated sheltered areas, the risk of mosquito-borne illness should be virtually eliminated in the greater Newburyport area.
Regardless, local officials are recommending that residents maintain their vigilance outdoors just in case.
“It didn’t wipe out 100 percent of the mosquito population, so we’re urging people to maintain their vigilance in personal protection when they’re doing activities outdoors,” Kezer said. “But with the decreased population, it mitigated a significant amount of the threat.”
The state Department of Public Health said that there have been a total of seven human cases of EEE this year, along with 24 human cases of West Nile virus, another less serious illness carried by mosquitoes.
The Centers for Disease Control and Protection describes EEE as a rare but serious illness spread by the bite of an infected mosquito. While EEE can infect people of all ages, people under 15 years of age or over 50 years of age are at greatest risk for serious illness, the CDC said.