September in Cypress averages a daily high of 32.7°C with nights around 20.8°C. Expect roughly 9.8 wet days totalling 98.3mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Cypress is February–April.
Based on HOUSTON HOOKS MEMORIAL AIRPORT, TX US (17.5km), 1995–2024. 27 years of September data.