September in Brownsville averages a daily high of 33.1°C with nights around 23.5°C. Expect roughly 11.2 wet days totalling 149.5mm. Demanding conditions — pack for it and plan indoor options.
Across the year, the best time to visit Brownsville is November–March.
Based on BROWNSVILLE S PADRE ISLAND INTERNATIONAL AIRPORT, TX US (8km), 1995–2024. 30 years of September data.