Japan: High temperatures forecast to persist across eastern and western regions through at least Sept. 19 /update 3

Forecast models indicate that high temperatures will persist across much of eastern and western Japan through at least Sept. 19. The Japan Meteorological Agency (JMA) has issued a weather bulletin advising that high pressure over the affected areas will lead to a continuation of warm temperatures through Sept. 19, with highs of over 35 C (95 F) possible in places. Heatstroke alerts have been issued for 15 prefectures across eastern and western Japan Sept. 17 and 18 prefectures Sept. 18. Warnings for temperatures over 31 C (88 F) are in place over much of the rest of the affected area. Officials will likely upgrade, rescind, or expand the coverage of alerts over the coming days as conditions change.

The extended period of oppressive heat and dry conditions may produce ideal circumstances for wildfire growth throughout the region. Heatwaves also threaten vulnerable groups - such as the elderly, children, pregnant women, and those with respiratory illnesses - due to the increased possibility of heat stroke or heat exhaustion during prolonged exposure to high temperatures. These health risks could also affect relatively healthy individuals during significant heatwave events.

High temperatures could warp rail tracks and force passenger and freight trains to operate at reduced speeds. Damage to road surfaces is also possible, and overheated vehicles could worsen traffic problems in urban areas where congestion is already a problem. Commercial trucking disruptions might occur, as very high temperatures put more stress on vehicles and make tire blowouts more common. Major flight disruptions are unlikely at regional airports; however, general aviation disruptions are possible, and some air freight carriers could reduce cargo loads. High temperatures could lead to an increased demand for electricity, which might trigger localized brownouts or blackouts, exacerbating hazardous conditions when air conditioning is no longer possible.