September in Perth averages a daily high of 20.6°C with nights around 9.7°C. Expect roughly 12.4 wet days totalling 79.2mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Perth is October–December.
Based on PERTH METRO, AS (3.8km), 1995–2024. 30 years of September data.