Western Australia weather in September
September is a fair month to visit Western Australia: highs of 18°C (65°F) and about 70 mm (2.8 in) of rain on average. Nights average 14°C (56°F) and cloud cover 53% (NASA POWER, 2001–2025 averages). The sea averages 18°C (64°F). It is the 5th wettest month of the year and the 3rd coolest. Compared with August, it is about as warm and drier; October brings highs of 20°C (68°F) and 32 mm (1.3 in) of rain.
Figures are long-term averages for Perth, the largest city in Western Australia. See below for other places.
Is September a good time to visit Western Australia?
fair month Weather score 72/100.
September is a fair month in Western Australia. The weather is usually best in Oct–Apr.
Does it rain a lot in Western Australia in September?
Some rain is normal: about 70 mm (2.8 in) falls in an average September. It is the 5th wettest month of the year.
How warm is Western Australia in September?
Days average 18°C (65°F) and nights 14°C (56°F).
Western Australia weather by month
| Month | High | Low | Rain | Cloud | Sea | Weather |
|---|---|---|---|---|---|---|
| January | 26°C (79°F) | 19°C (67°F) | 18 mm | 33% | 25°C (77°F) | best |
| February | 27°C (80°F) | 20°C (68°F) | 17 mm | 37% | 25°C (76°F) | best |
| March | 26°C (79°F) | 19°C (67°F) | 20 mm | 40% | 23°C (74°F) | best |
| April | 23°C (74°F) | 18°C (64°F) | 34 mm | 51% | 22°C (71°F) | best |
| May | 21°C (70°F) | 16°C (61°F) | 84 mm | 54% | 20°C (68°F) | fair |
| June | 19°C (66°F) | 15°C (58°F) | 113 mm | 59% | 19°C (66°F) | least pleasant |
| July | 18°C (64°F) | 14°C (57°F) | 128 mm | 60% | 17°C (63°F) | least pleasant |
| August | 18°C (64°F) | 14°C (56°F) | 106 mm | 58% | 17°C (63°F) | least pleasant |
| September | 18°C (65°F) | 14°C (56°F) | 70 mm | 53% | 18°C (64°F) | fair |
| October | 20°C (68°F) | 15°C (58°F) | 32 mm | 45% | 20°C (67°F) | best |
| November | 22°C (72°F) | 16°C (61°F) | 25 mm | 40% | 21°C (70°F) | best |
| December | 25°C (76°F) | 18°C (64°F) | 12 mm | 36% | 23°C (74°F) | best |
Sources: 2001–2025 monthly averages from NASA POWER (MERRA-2 reanalysis), sea temperature from Open-Meteo Marine. Page updated . How we rate months
Weather across Western Australia in September
Weather can differ a lot within Western Australia: coasts, hills and mountains each have their own climate.
| Place | High | Low | Rain | Weather |
|---|---|---|---|---|
| Perth | 18°C (65°F) | 14°C (56°F) | 70 mm | fair |
| Mandurah | 18°C (64°F) | 13°C (56°F) | 83 mm | fair |
| Bunbury | 17°C (63°F) | 9°C (49°F) | 89 mm | fair |
| Geraldton | 19°C (67°F) | 16°C (62°F) | 34 mm | fair |
| Baldivis | 18°C (64°F) | 13°C (56°F) | 83 mm | fair |
| Albany | 16°C (61°F) | 12°C (53°F) | 78 mm | least pleasant |
| Canning Vale | 18°C (65°F) | 14°C (56°F) | 70 mm | fair |
| Kwinana | 18°C (65°F) | 14°C (56°F) | 70 mm | fair |
| Kalgoorlie | 23°C (74°F) | 7°C (45°F) | 13 mm | best |
| Busselton | 17°C (63°F) | 9°C (49°F) | 89 mm | fair |
| Ellenbrook | 18°C (65°F) | 7°C (45°F) | 68 mm | fair |
| Dianella | 18°C (65°F) | 14°C (56°F) | 70 mm | fair |