A lot of health and school officials are no doubt breathing a sigh of relief this week now that NOAA’s National Weather Service and most local Massachusetts health boards confirmed that the Oct. 13 frost was hard enough to dramatically ease the threat of mosquitoes and mosquito-borne illnesses.
But here on the North Shore and in some southern New Hampshire communities, authorities say there is still cause for concern.
It all has to do with temperature. How cold was it and for how long? That’s what determines if enough mosquitoes survived to pose a continued threat of West Nile virus or Eastern equine encephalitis — better known as EEE.
Most local towns have ended the outdoor activity ban. Newburyport has yet to lift the ban. It may be of interest to parents to consider that the 10-day forecast for this area indicates there will be no frosts at night— and Halloween is less than a week away.
Hamilton was one of the last communities to lift a ban, making the move Wednesday night, a week before Halloween.
However, the town’s Board of Health still recommends that residents avoid outdoor activities due to the risk of mosquito-borne Eastern equine encephalitis.
“It’s a tough decision, but at this point in time, it’s the right decision,” Chairman Lindle Willnow said.
Willnow urged residents to continue to take “extreme precautions” when outdoors, covering as much skin as possible and using mosquito repellent. (Look for a lot of trick-or-treating mummies on Wednesday.)
The National Weather Service defines a hard freeze as temperatures dropping below 28 degrees at any time or at least below 32 degrees for three hours or longer. That was the case in the early morning hours of Saturday, Oct. 13, when the NWS said most of southern New England had a hard freeze.
But in parts of southern New Hampshire, the temperature did not get cold enough. The temperature dropped to 30 degrees, just slightly below freezing.
Early last week, a batch of mosquitoes from Stratham, N.H., tested positive for West Nile — a strong indication that people must still protect themselves from mosquitoes, according to Beth Daly, chief of infectious disease surveillance with the New Hampshire Department of Health and Human Services.
“We still think there is a risk out there,” Daly said. “People should continue to take precautions.”
While mosquito populations surely have been reduced by the cold weather, it is still worthwhile to take sensible precautions. With cooler temperatures, most people are likely wearing long sleeves and pants anyway.
Enjoy the fall weather and outdoor activities. At local high schools, it’s time for “Friday night lights” on the gridiron. At home, there is time for maybe one or two more cookouts before the snow flies.
Enjoy it all while it lasts.