September in Olathe averages a daily high of 26.6°C with nights around 15.2°C. Expect roughly 7.8 wet days totalling 85.9mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Olathe is September–October.
Based on OLATHE JOHNSON CO EXECUTIVE AIRPORT, KS US (7.7km), 1995–2024. 29 years of September data.