Heatwave kills four in Japan, alerts in place for the coming days
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.
Credit: Dom Pates
Four women between the ages of 65 and 96 died of suspected heatstroke amid record-high temperatures on June 17 in Japan’s Kanto and Chubu regions. Local emergency services confirmed the deaths occurred in Kanagawa, Shizuoka, Saitama, and Gunma Prefectures. A total of 226 people have sought emergency treatment for heat-related issues in the past two days.
The Japan Meteorological Agency (JMA) reported 65 out of 914 observation stations recorded temperatures at or above 35 °C (95 °F) on June 17. This rise in mercury was driven by warm air from the south and a high-pressure system.
The highest reading was 38.2 °C (100.8 °F) in Kofu, Yamanashi Prefecture, followed by 37.7 °C (99.9°F) in Takasaki, Gunma, and 37.6 °C (99.7 °F) in Shizuoka. Tokyo registered 34.8 °C (94.6 °F), Sendai 34.7 °C (94.5 °F), and Osaka 33.4 °C (92.1°F).
The agency reported that 547 locations across the country experienced daytime highs exceeding 30 °C (86 °F), making June 17 one of the hottest days ever recorded in Japan for the month of June. So far in June, record-high temperatures were confirmed in 14 cities, including central Tokyo, where the record temperature reached 34.4 °C (93.9 °F).
Heatstroke alerts were issued in multiple prefectures, including Ibaraki, Chiba, Wakayama, Kagoshima, Kagawa, Miyazaki and Okinawa. Authorities warned that heat-related illnesses were likely even with short exposure to outdoor conditions.
According to the Tokyo Fire Department, 57 people required emergency treatment for heatstroke on June 18, following 169 cases the previous day. JMA forecasts that the current heatwave will persist until at least June 20, with temperatures in Gifu and Nagoya expected to peak at 37 °C (98.6 °F), and Kyoto and Nara at around 36 °C (96.8 °F).
Recent government data shows that elderly individuals (65 and above) constitute more than 80 % of heatstroke fatalities. Consequently, health authorities have issued advisories that recommend staying indoors during the hottest parts of the day, drinking plenty of fluids, using fans and air conditioning, and avoiding straining activities outside during peak daytime hours.
References:
1 4 die of suspected heatstroke; more days of searing weather forecast – The Asahi Shimbun – June 18, 2025
2 Heat Stroke Alert – Heat Illness Prevention Information – June 19, 2025
3 Heatwave continues to grip Japan – NHK – June 18, 2025
4 Japan heatwave kills 3, sends over 220 to hospital amid record-breaking temperatures – Protothema – June 18, 2025
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