January in Hiroshima averages a daily high of 9.9°C. Expect roughly 5.7 wet days totalling 40.9mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Hiroshima is April–May.
Based on HIROSHIMA, JA (1.6km), 1995–2024. 23 years of January data.