September in Greeley averages a daily high of 28.4°C with nights around 9.7°C. Expect roughly 6.3 wet days totalling 28.7mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Greeley is September–October.
Based on GREELEY UNC, CO US (2.5km), 1995–2024. 29 years of September data.