Click on a day for an hourly weather forecast
The weather in Mount Isa in September is hot. The average temperatures are between 18°C and 31°C. Usually the days in September are hot while the nights are a bit cooler.
You can expect a few rainy days in Mount Isa during September, but usually the weather is comfortable in September.
Our weather forecast can give you a great sense of what weather to expect in Mount Isa in September 2025.
If you’re planning to visit Mount Isa in the near future, we highly recommend that you review the 14 day weather forecast for Mount Isa before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 35° / 26° | 7 | 24 | 0 | 221 mm | Bad | Mount Isa in January |
| February | 34° / 25° | 5 | 23 | 0 | 143 mm | Ok | Mount Isa in February |
| March | 34° / 24° | 3 | 28 | 0 | 105 mm | Ok | Mount Isa in March |
| April | 31° / 21° | 1 | 29 | 0 | 17 mm | Good | Mount Isa in April |
| May | 27° / 17° | 0 | 31 | 0 | 13 mm | Perfect | Mount Isa in May |
| June | 24° / 13° | 0 | 30 | 0 | 8 mm | Perfect | Mount Isa in June |
| July | 24° / 13° | 1 | 31 | 0 | 9 mm | Perfect | Mount Isa in July |
| August | 27° / 14° | 0 | 31 | 0 | 3 mm | Perfect | Mount Isa in August |
| September | 31° / 18° | 1 | 29 | 0 | 24 mm | Good | Mount Isa in September |
| October | 34° / 22° | 1 | 30 | 0 | 21 mm | Ok | Mount Isa in October |
| November | 35° / 25° | 2 | 28 | 0 | 58 mm | Ok | Mount Isa in November |
| December | 36° / 26° | 4 | 27 | 0 | 83 mm | Ok | Mount Isa in December |