The number of Massachusetts communities at the highest risk of coronavirus transmission dropped in half, nearly to single digits.
The town-by-town coronavirus data released Thursday showed 13 communities in the high-risk red zone, down from 26 last week. It's the fourth straight week the figure has declined; the most communities in the high risk "red zone" was in mid-January, when there were 229 cities and towns in it.
The town-by-town coronavirus risk data classifies communities' risk level on a scale from red, the highest, to grey, and is one of many metrics tracked by the state that had been showing the latest COVID surge subsiding, though others are also on the rise. (See this week's full list of red zone communities below.)
Get Boston local news, weather forecasts, lifestyle and entertainment stories to your inbox. Sign up for NBC Boston’s newsletters.
Massachusetts COVID Hot Spots
The following 13 communities are in the highest risk level as of Thursday: Brockton, Chicopee, Dracut, Edgartown, Haverhill, Lawrence, Littleton, Lowell, Nantucket, New Bedford, Rochester, Springfield and Taunton.
Of those communities, one is newly in red on the list this week: Rochester.
And 14 communities dropped out of red: Acushnet, Berkley, Fall River, Hampden, Lynn, Methuen, Palmer, Revere, Southbridge, Southwick, Tisbury, Wareham, Winchendon and Yarmouth.
To qualify for the red, high-risk category under the metrics, communities with populations under 10,000 must have more than 25 cases. For mid-size communities of between 10,000 and 50,000 people, they must have an average of more than 10 cases per 100,000 people and a positive test rate of more than 5%. And for larger communities of greater than 50,000 people, they must have more than 10 cases per 100,000 people and a positive test rate of more than 4%.
Get the latest news on COVID-19 delivered to you. Click here to sign up for our weekly coronavirus newsletter.
Previously, the state used the number of cases detected on average each day over two weeks to determine if Massachusetts' communities are at high risk for coronavirus transmission. The new list factors in population size and positive test rate.
See the full list, and the risk map itself, on the Massachusetts Department of Health COVID dashboard.