NEW CANAAN — Back-to-school wardrobes included face coverings as New Canaan students began returning to in-person classes Monday for the first time since the COVID-19 pandemic started.

Back on March 11, New Canaan students were sent home and immediately became immersed in distance learning. Sports seasons were canceled. Extracurricular activities were called off or radically changed, those that were held had to be conducted via cyberspace.

But that changed on Monday, as for the first time in five-and-a-half months students entered buildings, which were set up differently than they were pre-COVID. Directions are dictated in hallways to prevent crowding, masks are required, and there are physical barriers and efforts to maintain social distancing, including outdoor learning.

High school athletes have been given the green light to conditions for the fall season, but whether, or for how longs, games will be played remains unclear, with discussions continuing between the state Department of Health and the Connecticut Interscholastic Athletic Conference.

COVID cases have been reported in the area. While New Canaan reported Aug. 24 that none of the 641 teachers, school staff, parents and students tested positive for the virus, five residents did test positive around the same time. Two are students who have left New Canaan for college. All five who tested positive are asymptomatic and isolating at home, First Selectman Kevin Moynihan said.

New Canaan is phasing in the reopening of schools and elementary students have been divided based on last names, with Cohort X made up of students whose last names begin with the letters A to K, and Cohort Y with L to Z.

On the first day of school, other than kindergartners, Cohort X attended; on the second day Cohort Y; then that cycle repeats for the next two days.

Moving forward, students will attend classes with their cohort on Mondays and Tuesdays or Thursdays and Fridays. All attend every other Wednesday.

Kindergarten will start with half days, alternating Wednesdays, since Wednesday afternoons will be reserved for teacher training.

Starting the second week, students will learn remotely with livestreaming of the class when they are not in school.

In Phase II, students in kindergarten through fourth grade will be the first to go to 100 percent capacity, starting Monday, Sept. 21; grades 5-12 remain with the hybrid structure.

Phase III begins on Sept. 29 with grades 5-8 transitioning to five full days and Phase IV commences Oct. 5 with the full reentry of the high school students, which will complete the 100 percent student capacity.

Should schools need to close

Any decision to stay open or closed will be based on the average number of COVID-19 cases per 100,000 population in a seven-day period in Fairfield County, Superintendent of Schools Bryan Luizzi said.

The community spread is considered low when there is an average of 0 to 9 cases per 100,000 people for a seven-day period; community spread is labeled moderate when there are 10-24 cases per 100,000; and a high community spread would entail an average of 25 people, or more, with COVID-19 for every 100,000.

During “low community spread conditions, it is good to bring students back,” Luizzi explained. With moderate community spread, the district will “strengthen some mitigation strategies” and during high community spread, remote learning would be recommended, he said.

The metrics will be based on statistics for Fairfield County, because a few positive cases could skew the numbers in New Canaan with a population of only 20,000, Luizzi explained. In contrast, Fairfield County has nearly a million residents, he said.

Grace Duffield contributed to this story.