Update 2025-07-30 (4): According to media reports, a 50 centimetres high tsunami wave was measured in the port of Ishinomaki in Miyagi Prefecture. In the prefectures of Hokkaido, Aomori, Miyagi, Fukushima and Ibaraki, 40 centimetres high tsunami waves were observed, while 20-30 centimetres high tsunami waves were measured in the prefecture of Iwate. No tsunami waves were observed in Tokyo.
Update 2025-07-30 (3): The first waves on the east coast of Hokkaido amounted to around 0.3 meters.
Update 2025-07-30 (2): Further arrival times of waves are expected in Sapporo at 12:40 pm, in Shimizu at 12:44 pm, in Nobeoka at 12:50 pm, in Niigata at 12:59 pm, in Shimane at 1:58 pm, in Okinawa at 3 pm and Nagasaki at 3:33 pm (all in local time).
Update 2025-07-30 (1): According to initial forecasts, waves of between one and three metres are expected in Japan. The arrival time at 10:32 am, at Hachinohe 11:12 am, at Katsuura 11:22 am, at Hachijo Jima 11:34 am, and at Chichi Jima 12:03 pm (all figures in local time).