Key Facts
• July 21 (Mon, Holiday) marks Marine Day with widespread summer skies.
• High-pressure systems bring the hottest day of the three-day weekend.
• Over 35°C expected in many areas, including northern Japan (Aomori, Kitami).
• Kyoto and Maizuru forecasted to reach 38°C, surpassing body temperature.
• Heatstroke alerts issued in 26 prefectures, including Tokyo, nearing 35°C.
• Nagoya experiences its first heatwave in 11 days; Yamagata sees 4 consecutive days.
• Sudden weather changes likely in eastern Japan, especially inland areas.
• Thunderstorm probabilities increase compared to July 20 (Sun).
• Outdoor activities near mountains and rivers require caution due to unstable weather.
• Heatstroke prevention tips include frequent hydration, even during water activities.
Summary
On July 21, Marine Day, Japan experiences its hottest day of the three-day weekend, with temperatures exceeding 35°C across the country, including northern regions like Aomori and Kitami. Kyoto and Maizuru are expected to reach 38°C, while Tokyo nears 35°C, prompting heatstroke alerts in 26 prefectures. Sudden thunderstorms are likely, particularly in eastern Japan’s inland areas, as atmospheric instability increases. Outdoor enthusiasts are advised to stay vigilant, especially near mountains and rivers. Heatstroke prevention measures, such as frequent hydration, are crucial, even during water activities. The combination of extreme heat and unpredictable weather demands continued caution in the coming days.
