The Japanese government announced this week that much more must be done to prepare for a possible Nankai Trough “megaquake,” after a government panel raised the 30-year probability of a major event to up to 82 percent and new estimates projected as many as 298 000 fatalities and damages of up to USD 2 trillion.
Japanese authorities urged residents of Akusekijima Island to evacuate after another strong earthquake struck the region on July 3, 2025, the latest in a series of more than 1 000 quakes recorded since June 21.
A strong explosive eruption occurred at Shinmoedake volcano, part of the Kirishima volcanic complex on Kyushu Island, Japan, at approximately 15:37 JST (06:37 UTC) on July 3, 2025, sending an ash plume up to 6.7 km (22 000 feet) above sea level (a.s.l.). The Japan Meteorological Agency (JMA) had raised the volcanic alert to Level 3 on June 27, following increased volcanic unrest.
Japan recorded its hottest June since records began in 1898, with average temperatures 2.34°C (4.21°F) above normal and over 200 locations registering highs of 35°C (95°F) or more, the Japan Meteorological Agency reported on June 30, 2025.
An ongoing earthquake swarm in the Tokara Islands, southern Japan, has produced 474 tremors since June 21, 2025, with events reaching magnitudes up to M5.1 and a maximum local Japanese shindo intensity of 4.
A moderate eruption occurred at Mount Shinmoedake, part of the Kirishimayama volcano group in Kyushu, Japan, at approximately 16:37 JST (07:37 UTC) on June 22, 2025. The Japan Meteorological Agency reported an ash plume rising 500 m (1 640 feet) above the crater rim. The alert level remains at 2, with a 2 km (1.2 miles) exclusion zone around the crater.
At least four elderly women died of suspected heatstroke on June 17, 2025, in Japan’s Kanagawa, Shizuoka, Saitama, and Gunma Prefectures. More than 60 monitoring stations recorded temperatures at or above 35 °C (95°F). Temperatures are expected to rise until June 20, and a heat advisory is in place.
A strong and shallow earthquake registered by the JMA as M6.3 hit near the coast of Hokkaido, Japan, at 18:51 UTC on June 1, 2025 — 03:51 local time, June 2. USGS is reporting M6.0 at a depth of 31 km (19.2 miles).
A strong and shallow earthquake registered by the USGS as M6.1 hit near the coast of Hokkaido, Japan, at 08:37 UTC (17:37 local time) on May 31, 2025. The agency is reporting a depth of 10 km (6.2 miles). JMA is reporting M6.1 at a depth of 20 km (12.4 miles).
Three eruptions were recorded at Sakurajima volcano in Kagoshima Prefecture, Japan, on May 15, 2025, with ash plumes reaching heights over 4 200 m (13 800 feet) above sea level. Ashfall was reported in Kagoshima City, reducing visibility on city roads.
