PITTSBURGH — Our first summer heat wave kicked off today, and it will last through at least the middle of the week.

There's an "extreme" Level 4 heat warning for eight U.S. states on Sunday, June 22. The National Weather Service is warning eight U.S. states of extreme, dangerously high heat levels on Sunday. According to the Washington Post,

A prolonged period of very hot weather is expected through the middle of the week. During the latter portions of the week, storms will become more prominent in the afternoon and evening as a front approaches the DMV.