The 8.3 Mw Hokkaidō earthquake strikes just offshore Hokkaidō, Japan.

The 2003 Hokkaidō earthquake, scientifically named the 2003 Tokachi-Oki earthquake (十勝沖地震, 2003 Tokachi-Oki Jishin), occurred off the coast of Hokkaidō, Japan on 26 September at 04:50 local time (19:50 UTC 25 September). At a focal depth of 27 km (17 mi), this great undersea earthquake measured 8.3 on the moment magnitude scale, making it the most powerful earthquake of 2003, as well as one of the most intense earthquakes to hit Japan since modern record-keeping began in 1900.

The Hokkaido earthquake caused extensive damage, destroying roads all around Hokkaidō, and triggered power outages and extensive landslides. Over 800 people were injured. The earthquake also caused a tsunami reaching 4 meters in height. The earthquake's presence was felt throughout Japan, stretching all the way to Honshu and Tokyo.