Phoenix weather in September
September in Phoenix: sweltering, a little rain, with clean air — a gamble, with 38°C afternoons.
#9 of 12 months in Phoenix · #829 of 897 destinations to visit in September · comfort 56/100 (tier D)
Updated June 2026 · climate normals from ERA5 reanalysis
Traveller notes on Phoenix in September
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Phoenix climate normals — September
| Daytime high | 38°C / 100°F | 🔥 sweltering |
|---|---|---|
| Nighttime low | 25°C / 76°F | |
| Rainfall | 34 mm / 1.3 in | 🌦 some rain |
| Rainy days | 4 days | |
| Humidity | 35% | 🌵 dry |
| Dew point | 11°C / 53°F | |
| Sunshine | 11.1 h/day | |
| Daylight | 12.4 h | |
| Wind | 14 km/h / 9 mph | |
| Air quality (US AQI) | 45 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
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Phoenix in September — FAQ
- Is September a good time to visit Phoenix?
- September in Phoenix: sweltering, a little rain, with clean air — a gamble, with 38°C afternoons. It ranks #9 of 12 months for Phoenix on SeasonMap's comfort score (56/100).
- What is the weather like in Phoenix in September?
- In September, Phoenix averages a daily high of 38°C and a low of 24.6°C, with about 34.1 mm of rain over roughly 3.8 rainy days.
- What is the air quality in Phoenix in September?
- Phoenix has a mean US Air Quality Index of about 45 in September.