Phoenix weather in August
In August, Phoenix has an average high of 41 °C105 °F and an average low of 27 °C81 °F, with about 33 mm1.3 in of precipitation. It is the 2nd warmest month of the year and the wettest.
How August compares with other months
Compared with July, August is 0.9 °C1.7 °F cooler on average. Compared with September, August is 3 °C5.4 °F warmer on average and wetter by 11 mm0.4 in. Daylight lasts about 13.4 hours around the middle of the month. Average relative humidity is 35% and the average cloud amount 38%.
Is August a good time to visit Phoenix?
August is not among the most comfortable months by our comfort score: it is hot (average high 41 °C105 °F). The most comfortable months in Phoenix are November–March.
What to wear in August
For Phoenix in August, pack very light, breathable clothing, a sun hat and plenty of water.
August in nearby places
| Place | High °C°F | Low °C°F | Precip. mmin |
|---|---|---|---|
| Phoenix | 41105 | 2781 | 331.3 |
| Peoria | 41105 | 2781 | 281.1 |
| Mesa | 40105 | 2781 | 331.3 |
| Tucson | 3697 | 2474 | 652.6 |
| Yuma | 41106 | 2780 | 130.5 |
| Nogales | 3391 | 2068 | 763.0 |
| San Luis Río Colorado | 43109 | 2780 | 80.3 |
| Mexicali | 44111 | 2882 | 70.3 |
| Henderson | 41105 | 2679 | 150.6 |
Nearby places that are more than 1 °C1.8 °F warmer in August: Mexicali; cooler: Tucson and Nogales.
Other months in Phoenix
- January19 °C67 °F / 6 °C42 °F
- February21 °C70 °F / 7 °C44 °F
- March26 °C78 °F / 10 °C50 °F
- April30 °C86 °F / 13 °C56 °F
- May35 °C96 °F / 18 °C65 °F
- June42 °C107 °F / 24 °C76 °F
- July42 °C107 °F / 28 °C83 °F
- August41 °C105 °F / 27 °C81 °F
- September38 °C101 °F / 24 °C75 °F
- October32 °C90 °F / 17 °C63 °F
- November25 °C77 °F / 11 °C51 °F
- December19 °C66 °F / 5 °C42 °F
Frequently asked questions
How warm is Phoenix in August?
In August the average high in Phoenix is 41 °C (105 °F) and the average low is 27 °C (81 °F).
Does it rain a lot in Phoenix in August?
On average about 33 mm (1.3 in) of precipitation falls in August; it ranks 1st of the 12 months.
Is August the warmest month in Phoenix?
No. The warmest month in Phoenix is July, with an average high of 42 °C (107 °F). The coldest month is December, with an average low of 5 °C (42 °F).
How long is the day in Phoenix in August?
In the middle of August the day in Phoenix lasts about 13.4 hours from sunrise to sunset. The value is calculated from the position of the city and the sun.
How humid is Phoenix in August?
The average relative humidity in August is about 35%. This is a long-term average for the whole day.
How cloudy is Phoenix in August?
On average about 38% of the sky is covered by cloud in August. This is the mean cloud amount from satellite data, not the number of sunny days.
About this data
All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station, so they can differ from airport records — most of all on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.
The grid cell’s average elevation is 494 m, while Phoenix lies at about 331 m. Temperatures on this page were therefore adjusted by +1.1 °C1.9 °F using the standard lapse rate of 6.5 °C per 1,000 m.