In this Thursday, Sept. 14, 2017, photo students head for their buses at York Middle School in York, Maine. Credit: Robert F. Bukaty / AP

It’s safe for schools in Maine’s southernmost county to open for full-time, in-person instruction for the first time in more than a month, according to state officials.

The Maine Department of Education on Friday moved York County back to “green” territory for the first time since early September. It cited falling rates of new cases and positive coronavirus tests in moving York County back to the school safety designation of Maine’s 15 other counties.

It was a sign that the spread of the coronavirus in York County has largely stabilized since mid-August, when York County absorbed the brunt of the impact of an outbreak traced back to an Aug. 7 wedding in the Katahdin region.

Two York County outbreaks were linked directly to that wedding — an outbreak at the York County Jail that became Maine’s largest outbreak to date in a correctional facility, and an outbreak at the Sanford Calvary Baptist Church whose pastor officiated the Aug. 7 wedding and continued to defy state mask-wearing and social-distancing rules aimed at stemming the virus’ spread.

The spread of the virus intensified in York County from there, with outbreaks at private social clubs, businesses and a number of other establishments. The city of Sanford, in particular, became an epicenter for the virus’ spread. The state’s top public health official warned that Maine — which has had some of the lowest COVID-19 infection, death and hospitalization rates in the country — could lose control of its coronavirus outbreak because of the rapid spread in York County.

Shah on Thursday, however, said the state had officially closed the York County Jail outbreak, because the facility hadn’t seen a new case in at least 28 days.

York County’s case numbers have been falling in recent weeks. The southern Maine county of about 200,000 residents no longer has the highest rate of new cases; that designation belongs to rural Somerset County, where the virus has been circulating more recently. And York County no longer has the state’s highest rate of positive coronavirus tests; that designation now also belongs to Somerset County, according to Maine CDC data. York County’s rate of positive tests has fallen below 1 percent, with 0.9 percent of COVID-19 tests coming back positive over the past weeks. That rate is higher than the statewide rate of 0.5 percent over the same time period, but lower than Somerset County’s 1.3 percent rate.

State health officials say they’re also keeping a close eye on Androscoggin County, which has seen some of the state’s highest rates of new cases and positive tests lately. Last week, the state upgraded its school safety rating for Oxford County from yellow to green after a surge in cases stabilized in that rural county. Oxford had been the only other county besides York to not be classified as green.

While York County schools now have the green light to open full-time for in-person instruction, the county is still home to the highest number of school virus outbreaks. Of four active school virus outbreaks, three are in York County — at Sanford High School, Coastal Ridge Elementary School in York and Massabesic Middle School in Waterboro.

Although most of the state’s schools have had the green light to open full time in person, most have employed a hybrid model in which students attend school a few days a week and learn at home the rest.