First warning of dangerous heat in Arizona midweek

PHOENIX (AZFamily) — We have declared FIRST ALERT weather days this week for extreme heat, beginning Wednesday and continuing through Friday night. Daytime highs will be between 41 and 44 degrees, with a slight rebound overnight, with lows between 24 and 29 degrees.

This heat is caused by a high pressure system building up from the west and settling directly above us. Since these temperatures are well above average, the risk of heat is high for sensitive people, the elderly and children.

Be sure to open trail closures and cooling stations throughout the valley by mid-week.

A heat warning will be issued for large parts of the state starting Wednesday. This heat will be accompanied by health-threatening ozone levels. High air pollution warnings will be in effect for Maricopa and Pinal counties tonight and Tuesday.

These warnings will be extended later in the week as the heat increases. The ridge of high pressure will weaken over the weekend and temperatures will remain hot but should fall below 40 degrees in the afternoon.

The valley will remain dry for at least the next week, but isolated thunderstorms may occur in the higher elevations in the north and east of the valley by the weekend.

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