The hottest large city in the United States broke its previous record of 76 consecutive 100F days set in 1993. The relentless streak, which started on 27 May and hit its 100th day on Tuesday, is forecast to persist into next week. An excessive heat warning is in effect through Friday, with temperatures expected to reach 110F (43C) tomorrow. This summer was the hottest one in Phoenix since 1896, when records first began. Latest county data shows that at least 177 people died from heat-related causes so far this year, with 436 under investigation. Last year, Maricopa county saw 645 confirmed heat-related fatalities, enduring 55 days in a row with above 110F temperatures.