September in Amarillo averages a daily high of 29°C with nights around 14.3°C. Expect roughly 5.6 wet days totalling 41.4mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Amarillo is March–May.
Based on AMARILLO AIRPORT, TX US (11.2km), 1995–2024. 30 years of September data.