August in Iwamizawa averages a daily high of 26.3°C. Expect roughly 12.1 wet days totalling 172.5mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Iwamizawa is June–September.
Based on IWAMIZAWA, JA (2.6km), 1995–2024. 24 years of August data.