It’s time to crank up those air conditioners, because the heat wave has arrived.

All across Southern California, temperatures will crest into the triple digits and likely break records. By Monday, the Inland valleys could see highs greater than 108 and the deserts could see highs greater than 120. The high temperatures have prompted the National Weather Service to put out an excessive heat warning that will last through Monday for coastal areas, Tuesday for the Inland valleys and Wednesday for the mountains and deserts.