Mid-summer temperatures in Phoenix (from June to August) average just under 40°C (104°F), with many days above that figure. Afternoon thunderstorms and flash flooding occurs during this time. By December the weather has cooled down, remaining mild until April, when the heat comes back with force. Phoenix does not get much rain across its cooler months.
| Month | Temp (°C) | Rainfall (mm) | Humidity (%) | Sunshine (hours) |
| Jan | 4 - 18 | 20 | 8 | |
| Feb | 6 - 21 | 20 | 10 | |
| Mar | 8 - 24 | 18 | 11 | |
| Apr | 12 - 28 | 10 | 12 | |
| May | 16 - 33 | 3 | 13 | |
| Jun | 21 - 38 | 3 | 14 | |
| Jul | 25 - 40 | 25 | 13 | |
| Aug | 24 - 38 | 25 | 12 | |
| Sep | 21 - 36 | 18 | 12 | |
| Oct | 13 - 30 | 10 | 10 | |
| Nov | 7 - 24 | 15 | 9 | |
| Dec | 4 - 19 | 23 | 9 |