At 4:00 p.m. on Sunday, June 21, 2026, the Fukuoka District Meteorological Observatory raised the volcanic alert level for Mt. Aso to Level 2 (Crater Area Restriction). As a result, entry within approximately 1 km of the Nakadake crater is now prohibited, and direct viewing of the crater is not possible until the alert is lifted.
In Japan’s five-tier volcanic alert system, Level 2 means the danger zone extends beyond the crater rim itself — in this case, a roughly 1 km radius around Nakadake. This does not mean the entire Aso mountain area is off-limits. The Aso Volcano Museum, the wider Kusasenri plateau, and other sightseeing spots outside the exclusion zone remain accessible. That said, anyone planning to hike Nakadake or Takadake should check the latest conditions before heading out, as trail access near the summit will be affected.
The Nakadake crater rim was already closed for emergency works through July 31 — this new alert level reinforces and expands those restrictions based on current volcanic activity. Visitors who do make it to the mountain area should follow all instructions from on-site staff.
For the most up-to-date exclusion zone maps and activity reports, check the Japan Meteorological Agency’s Mt. Aso activity page. Conditions can change quickly, so it’s worth bookmarking before your trip.
Source: 阿蘇火山博物館
