TOKYO – The Japanese weather agency said intense heat is expected again across wide areas of the country on Wednesday, while warning against unstable atmospheric conditions in northeastern Japan.

The Japan Meteorological Agency (JMA) expected temperatures to rise again to similar levels across the country after the mercury surpassed 40 degrees Celsius in the central prefectures of Gifu and Aichi the previous day.

The JMA forecast daytime highs of 40 C in Kumagaya city and Nagoya city, 39 C in the cities of Maebashi, Saitama, Kofu and Gifu, 38 C in the cities of Kyoto, Takamatsu, Okayama and Hita, 37 C in central Tokyo and Osaka city.

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The agency has issued heatstroke alerts in 41 prefectures from the Tohoku region to Okinawa.

A total of 287 people aged between 3 and 103 were taken to hospital on Tuesday in Tokyo, seemingly suffering from heatstroke, according to the Tokyo Fire Department.

Weather officials urged people to use air conditioners, drink adequate amounts of water, take salt to avoid heatstroke, and avoid long outdoor activities.

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Meanwhile, moist air flowing into a weather front is making atmospheric conditions unstable over Tohoku. Some parts of the region may receive 40 millimeters per hour of rain, accompanied by lightning.

The JMA urged residents to remain vigilant against landslides, flooding in low-lying areas, swollen rivers, as well as lightning and gusty winds.