Phoenix Weather August 2025. During july and august, there is an increase in humidity, and there is often considerable afternoon and evening cloudiness associated with. The peak temperatures often soar to about 104.5°f (40.3°c), making it one of.

Expect 39°c daytime maximum temperatures in the shade with on average 12 hours of sunshine per day in phoenix in august. Explore comprehensive august 2025 weather forecasts for phoenix, including daily high and low temperatures, precipitation risks, and monthly temperature trends.