At least 1,000 schools in 35 states have closed for in-person learning since the start of the school year

At least 1,000 schools across 35 states have closed for in-person learning because of COVID-19 since the beginning of the school year, according to Burbio, a New York-based data service that is tracking K-12 school reopening trends.

Schools listed in the company's tracker have closed for anywhere from one day to several weeks. Most temporarily moved to remote learning. Others temporarily closed with no instruction. And a small number delayed the start of school or shifted into hybrid learning, according to Burbio.

The rising number of closures comes amid a battle over mask...