Arizona weather in August
August splits Arizona wide open: Phoenix runs 105° afternoons while Flagstaff tops out near 79°.
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 99–105°, nights 75–84°, and 0.9–2.0 in of rain in a typical August.
Red Rock Country
Highs near 94°, nights around 67°, and 2.0 in of rain in a typical August.
| Place | Highs / lows | Wet days | The short version |
|---|---|---|---|
| Sedona | 94° / 67° | 5 | The greenest weeks of the year, and the loudest skies. |
High Country
Highs 79–82°, nights 50–51°, and 2.2–3.0 in of rain in a typical August.
| Place | Highs / lows | Wet days | The short version |
|---|---|---|---|
| Flagstaff | 79° / 51° | 7 | Rain most afternoons, green everywhere, evenings worth sitting out for. |
| Grand Canyon | 82° / 50° | 5 | Storms build daily, lightning on the overlooks, canyon still baking. |
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.