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15 Aug 2023 | 09:26 AM UTC

Japan: High temperatures forecast to persist across parts of the country through at least Aug. 21

High temperatures forecast across parts of Japan through at least Aug. 21. Transport, utility disruptions possible. Health concerns likely.

Informational

Event

Forecast models indicate that high temperatures will persist across parts of Japan through at least Aug. 21. Temperatures of 39 C (102 F) were recorded in Niigata Prefecture and 38 C (100 F) in Gifu Prefecture Aug. 14 and high temperatures are expected to continue especially in areas along the Sea of Japan coast from Aug. 15. The Japan Meteorological Agency (JMA) has issued a bulletin warning that high pressure will lead to an extended period of high temperatures in parts of eastern and northern Japan through Aug, 21, with highs of over 35 C (95 F) in places.

The JMA has issued heat stroke alerts across Akita, Chiba, Ishikawa, Kagoshima, Miyazaki, Niigata, Toyama, and Yamagata prefectures Aug. 15, as well as Okinawa main island and the Miyako and Yaeyama islands in Okinawa Prefecture. Further heat stroke alerts are in place for Fukui, Hiroshima, Hyogo, Kagawa, Kagoshima, Kyoto, Kumamoto, Iwate, Nagasaki, Okayama, Toyama, and Wakayama prefectures and the Yaeyama Islands Aug. 16. Authorities may update, extend, or rescind advisories as weather conditions change over the coming days.

Hazardous Conditions
The extended period of oppressive heat and dry conditions may produce ideal circumstances for wildfire growth throughout the region. Heatwaves also pose a threat to 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 extend to relatively healthy individuals during significant heatwave events.

Transport and Utilities
Very 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 airfreight 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.

Advice

Monitor local media for weather updates and related advisories. During heatwaves, remain indoors in air conditioning when possible. If outdoor activities are necessary, frequently rest in shaded areas; avoid activity during the hottest times of the day. Stay well-hydrated by drinking plenty of fluids. Avoid caffeinated and alcoholic beverages, which are dehydrating. Wear loose-fitting, light-colored clothing. Cotton fabrics are more cooling than synthetics. Promptly seek medical attention if signs of heat exhaustion or heat stroke develop. Charge battery-powered devices in case prolonged electricity outages occur.

Resources

Japan Meteorological Agency (JMA)