First Alert Weather Days remain in effect as intense heat grips the Valley through the weekend. Phoenix is expected to reach about 111 degrees today, with highs at or above 110 degrees likely through Sunday. The city also set a record warm low of 92 degrees, leaving little overnight relief. A slight chance of rain and thunderstorms returns to the Valley on Wednesday and Thursday nights. Storm coverage is expected to increase across the Mogollon Rim and northern Arizona later this week and into the weekend.