Arizona weather in September

September splits Arizona wide open: Phoenix runs 100° afternoons while Flagstaff tops out near 74°.

Based on 5 weather stations. Five stations from the desert floor to seven thousand feet — Arizona is really two climates stacked a mile apart, and the rows below keep them separate.

The Desert

Highs 95–100°, nights 70–78°, and 0.6–1.3 in of rain in a typical September.

Place	Highs / lows	Wet days	The short version
Phoenix	100° / 78°	1	Hot right through, with relief teasing at the end.
Tucson	95° / 70°	2	Storms taper off, heat hangs on, evenings improve slowly.

Red Rock Country

Highs near 89°, nights around 61°, and 1.7 in of rain in a typical September.

Place	Highs / lows	Wet days	The short version
Sedona	89° / 61°	3	The rocks glow longer each evening and the crowds return.

High Country

Highs 74–76°, nights 43–44°, and 1.5–1.8 in of rain in a typical September.

Place	Highs / lows	Wet days	The short version
Flagstaff	74° / 43°	4	Golden aspens, warm sun, and mornings that bite.
Grand Canyon	76° / 44°	3	Warm, calm, and the easiest hiking of the year.

Each place above has its own page for the full story — what the month feels like, what to pack, and whether the timing is right.

Where to go in September, across the whole country ›