September in Billings averages a daily high of 25.8°C with nights around 8.2°C. Expect roughly 6.2 wet days totalling 35.4mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Billings is June.
Based on BILLINGS WATER TREATMENT PLANT, MT US (2km), 1995–2024. 29 years of September data.