Japan heatwave and thunderstorms trigger flood and lightning alerts

On July 27‑28, 2026, Japan experienced a contrast of weather conditions. Western regions enjoyed clear skies and a continuing heatwave, while eastern and central areas faced rapid changes. The Pacific high‑pressure system kept the west hot, but the Kanto mountains and inland Shizuoka were forecast to see sudden thunderstorms and heavy rain.

In Fukushima Prefecture, forecasters warned of widespread intense thunderstorms, heavy downpours, possible road flooding, lightning surges and power outages. Residents were advised to avoid low‑lying areas, secure outdoor equipment and monitor local alerts. Similar risks of flash flooding and lightning were highlighted for other eastern prefectures, with particular attention to the Kanto mountain belts.