September in Dublin averages a daily high of 18°C with nights around 9.8°C. Expect roughly 13.9 wet days totalling 61.7mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Dublin is June–September.
Based on DUBLIN PHOENIX PARK, EI (5.8km), 1995–2024. 29 years of September data.