LAWRENCE, Mass. (AP) — The new school year in Massachusetts has just started but already some school districts are cutting classes short because the heat.

The Lawrence and Haverhill public school districts have announced that until Thursday schools will release early every day. There will be no preschool in Lawrence all week.

The National Weather Service has declared an excessive heat watch or a heat advisory for all of Massachusetts through Wednesday, as temperatures could reach into the upper 90s in some areas.

Most schools in Massachusetts are not air conditioned.