Perth has a long, hot summer (December to March) where little rain falls and the temperature can stay up around 30°C (86°F), especially in January and February. A late afternoon breeze off the sea, known as the 'Fremantle Doctor', helps cool the city. Winter brings coolish weather and rain, with an average temperature of 18°C (64°F).
| Month | Temp (°C) | Rainfall (mm) | Humidity (%) | Sunshine (hours) |
| Jan | 17 - 29 | 8 | 10 | |
| Feb | 17 - 29 | 10 | 10 | |
| Mar | 16 - 27 | 20 | 9 | |
| Apr | 14 - 24 | 43 | 7 | |
| May | 12 - 21 | 130 | 6 | |
| Jun | 10 - 18 | 180 | 5 | |
| Jul | 9 - 17 | 170 | 5 | |
| Aug | 9 - 18 | 145 | 6 | |
| Sep | 10 - 19 | 86 | 7 | |
| Oct | 12 - 21 | 56 | 8 | |
| Nov | 14 - 24 | 20 | 10 | |
| Dec | 16 - 27 | 13 | 10 |