August in Tallinn averages a daily high of 21.3°C with nights around 12.5°C. Expect roughly 13 wet days totalling 80.2mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Tallinn is June–August.
Based on TALLINN, EN (9.6km), 1995–2024. 30 years of August data.