St Helens in September
September in St Helens is peak spring, and the weather reflects it. You're looking at average daily highs of 15.2 degrees.
Expect the mercury to hit around 15.2 degrees during the day and settle at 7.5 degrees after dark. The temperature stays pretty consistent through the day. Manageable with a decent layer, and you'll warm up by midday.
At 15.2 degrees, September sits 2.6 degrees below the annual average of 17.8 degrees.
You're looking at 87mm of rain across 11 days in a typical September. A decent amount, but not relentless.
Solar exposure averages 13.4 MJ/m2 per day in September, with UV levels in the high range. Sun protection is still a good idea, especially around midday.
September scores 3.2/10 on our Comfort Score. It's the tough end of the year weather-wise.
Packing tip: bring layers you can peel on and off, waterproof gear, and SPF 50+ sunscreen and a hat.
The full data breakdown is below. You can also see how other Australian cities compare in September.
September at a Glance
Temperature Range
Daily temperature range in September. The bar shows the typical spread between overnight lows and afternoon highs.
What to Pack
- Layered clothing for mild to cool conditions
- A warm jumper or fleece for cool mornings and evenings
- A waterproof jacket or compact umbrella
Coming From Overseas?
How September in St Helens stacks up against major cities around the world.
About 5 degrees cooler and considerably wetter.
About 11 degrees cooler and considerably drier.
About 12 degrees cooler and considerably drier.
How September Compares
St Helens's monthly climate at a glance. September is highlighted.
| Month | Max | Min | Rain | Comfort |
|---|---|---|---|---|
| Jan | 22.3 | 13.9 | 41mm | 9.5 |
| Feb | 23.5 | 13.1 | 80mm | 10.0 |
| Mar | 21.5 | 12.1 | 35mm | 8.6 |
| Apr | 18.0 | 9.3 | 70mm | 5.5 |
| May | 15.3 | 8.2 | 81mm | 2.5 |
| Jun | 12.6 | 6.2 | 79mm | 1.0 |
| Jul | 12.1 | 5.3 | 125mm | 1.0 |
| Aug | 15.0 | 8.3 | 61mm | 2.6 |
| Sep | 15.2 | 7.5 | 87mm | 3.2 |
| Oct | 17.2 | 8.2 | 56mm | 5.7 |
| Nov | 19.1 | 10.8 | 158mm | 5.9 |
| Dec | 22.1 | 12.1 | 49mm | 9.5 |