Will I be hot?
Will I be hot in Phoenix in September?
Verdict
Yes — Yes, hot.
Highs push 99°F — sun exposure and hydration matter more than layering.
Day vs. night
Day
99°F
Sweltering
Plan indoor hours around the peak of the day.
Night
75°F
Warm
Still warm enough for a T-shirt after dark.
Why
Phoenix in September averages highs of 99°F, lows of 75°F, 3 rainy days.
Prioritize breathable fabrics, sun protection, and hydration over any kind of layering piece.
Nearby months
Packing pointers
Best shoes
Breathable shoes & sandals for Phoenix in September →