About 42,000 Atlanta students headed back to classes Wednesday on Atlanta Public Schools’ first day of school.

That’s an increase of about 250 from last year. District officials expect more students to arrive in the coming days.

“Things have gone very smoothly so far,” Deputy Superintendent David Jernigan said late Wednesday afternoon. “There’s a lot of positive energy and excitement in the air.”

Atlanta hired 432 teachers over the summer and started the school year with just nine teacher vacancies, Jernigan said. Eighteen schools have new principals.

Some Atlanta schools got air conditioning and heating system upgrades, too. Earlier this year, the district used $38.9 million from a voter-approved sales tax, or SPLOST, to replace and repair HVAC systems at 18 schools. Major projects are in the works for about six other schools.

“We’re still going to have some spots that are tough in our older buildings, but the ones that we’re working on will absolutely have better air,” Superintendent Meria Carstarphen said last month.

Students in Cobb County went back to school Monday. For Fulton, Gwinnett and DeKalb schools, the start date is Aug. 10.