Expo 2027 safety councils review a draft lightning evacuation plan; detailed plans due autumn 2026

• On 1 October the association posted reports on three meetings held over the summer: the 5th Safety Measures Council (21 August), the 4th meeting of its Fire and Disaster Prevention Subcommittee (24 July) and the 4th Medical and First Aid Council (28 July), all at the association’s offices. The English names of these bodies and plans are trip-jp’s own renderings.
• Safety council and subcommittee: The association explained how its on-site General Command Centre will be run and outlined its lightning measures. Members commented on the centre’s operation, on how weather information will be gathered, and on a draft evacuation plan for lightning. A draft Fire and Disaster Prevention Implementation Plan was also presented. Council members stressed realistic drills and communications after a major earthquake.
• Medical council: Members commented on the medical set-up at the venue and on the direction of the Medical and First Aid Implementation Plan.
• The only documents attached are each council’s rules. The draft plans themselves are not posted.
• The basic plans underneath were published on 27 October 2025: fire and disaster prevention, medical and first aid, and venue hygiene. A reference sheet released the same day says the implementation plans are to be adopted around autumn 2026.
• Lightning in the basic plan: Using Japan Meteorological Agency data, the plan counts 52 thunder days in Yokohama in 2024, 34 of them in July to September. By month: 2 in March, 2 in April, 1 in May, 5 in June, 12 in July, 16 in August and 6 in September. August had at least 7 in each of the five years from 2020. Outdoor event spaces where many people gather are named as high-risk. The main responses are moving people away from high places and trees, guiding them indoors, and considering the cancellation of outdoor events.
• Medical care in the basic plan: AEDs will be placed outdoors, each covering a circle 150 m across, so one can be attached within three minutes of a cardiac arrest. On-site care is first aid, paid for by the association. The number and location of aid stations will be set in the implementation plan.

Our take

Read month by month, the thunder table in the basic plan splits the Expo season in two. In Yokohama in 2024 there were one or two thunder days a month from March to May and five in June, then 12 in July, 16 in August and six in September. The Expo runs from 19 March to 26 September 2027, so the three stormiest months fall on its final stretch. This summer the association took lightning to both the subcommittee and the full council as an item of its own, with a draft evacuation plan.

The responses the basic plan lists for lightning are moving people away from high places and trees, guiding them indoors, and considering the cancellation of outdoor events. The same plan counts outdoor event spaces that draw crowds among the high-risk spots. We think the evacuation plan will therefore centre on two things: the threshold for stopping outdoor events, and which buildings each area’s visitors are sent to.

Both belong to the implementation plans due around this autumn. So do the number and location of aid stations, the AED layout, and the temporary shelters for visitors who cannot get home, all of which the basic plan leaves to the implementation stage.

Tips for visitors

• If you can choose your month, spring has the least thunder. In the plan’s table for 2020 to 2024, Yokohama had 1 to 3 thunder days in March, 2 to 4 in April and 1 to 4 in May. Temperatures and how reservations fill up are in when to visit the Yokohama Expo.
• For a visit in July to September, check the morning forecast for a thunderstorm advisory and afternoon storms. If thunder starts while you are on site, the basic plan’s response is to leave high ground and trees and go indoors. Follow the announcements and staff directions.
• Outdoor events may be called off when lightning threatens. If an event is your reason for a summer visit, decide beforehand which indoor exhibits you would see instead, so the day still works if the event is cancelled.
• For the heat side of a summer visit, see our news on water refill spots at the venue.