PHILADELPHIA (AP) — Schools in Philadelphia will be sending students home early again Thursday due to continued high temperatures.

The School District of Philadelphia said all schools will dismiss students at noon Thursday, as was the case Wednesday. All after-school activities including all athletic programs and professional development sessions are canceled.

The National Weather Service has issued a heat advisory for the region until 7 p.m. Wednesday, warning of temperatures in the lower 90s and maximum heat index values near 100.

Students were also sent home early from Philadelphia schools for three days last week, with officials saying high temperatures into the evening meant many buildings weren't cooling overnight. Only 27 percent of the district's school buildings have central air conditioning.