Last updated: June 24, 2025
In Phoenix, United States, the average temperature in September hovers around 18°C (65°F), with minimums dipping to 4°C (39°F) and maximums rising to a warm 32°C (91°F). During this month, expect about 87 mm (3.4 in) of precipitation spread over 10 days, contributing to an average humidity level of 78%. Stay prepared for a mix of mild temperatures and occasional showers!
In September in Phoenix, the average temperature is 18°C (65°F). Maximum temperatures can reach 32°C (91°F), while minimums can drop as low as 4°C (39°F). This varied climate makes Phoenix an ideal destination for travelers seeking both warm days and cool evenings.
In Phoenix in September, the precipitation amount is 87 mm (3.4 in) over the course of 10 days.
In Phoenix in September, humidity is 78%. With an average temperature of 18°C (65°F), this humidity feels like a warm, enveloping blanket, making travel quite muggy and potentially uncomfortable, as it can leave you feeling sticky and fatigued more quickly than usual.
In Phoenix in September, the maximum UV index is 7, which corresponds to the high Exposure Category. This means that the time to burn is approximately 25 minutes. For more detailed information, you can check the Hourly UV Index in Phoenix.
UV Risk Categories
Weather in Phoenix varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Phoenix, focusing on differences in temperature, rainfall, humidity, and UV levels.
Temperature | Precipitation | Humidity | UV | |
---|---|---|---|---|
January Weather | -3°C (27°F) | 97 mm (3.8 inches) | 90% | moderate |
February Weather | -2°C (29°F) | 98 mm (3.9 inches) | 90% | moderate |
March Weather | 1°C (35°F) | 91 mm (3.6 inches) | 87% | high |
April Weather | 7°C (46°F) | 122 mm (4.8 inches) | 88% | very high |
May Weather | 14°C (57°F) | 119 mm (4.7 inches) | 82% | very high |
June Weather | 19°C (67°F) | 100 mm (3.9 inches) | 79% | very high |
July Weather | 23°C (73°F) | 175 mm (6.9 inches) | 78% | very high |
August Weather | 22°C (72°F) | 124 mm (4.9 inches) | 76% | very high |
September Weather | 18°C (65°F) | 87 mm (3.4 inches) | 78% | high |
October Weather | 13°C (55°F) | 170 mm (6.7 inches) | 84% | high |
November Weather | 5°C (41°F) | 115 mm (4.5 inches) | 89% | moderate |
December Weather | 0°C (33°F) | 114 mm (4.5 inches) | 86% | low |