Japan's season of heat and rain nears

NHK

21-05-2025

As the clock ticks down to late May, Japan is bracing for its season of rain and heat. Officials in turn warn of the perils that accompany excessive humidity and scorching temperatures, and how to cope.
Summer-like heat gripped eastern and western Japan on Tuesday due to sunny conditions brought by a high-pressure system, and warm air flowing in. The scorching temperatures are set to continue at least through Wednesday.
By Tuesday afternoon, the temperature had soared to 34 degrees Celsius in Yamanashi Prefecture's Otsuki city, 33.5 degrees in the western Tokyo city of Hachioji, 33 degrees in Fukuoka Prefecture's Itoshima city and Hyogo Prefecture's Asago city. The temperature topped 30 degrees in central Tokyo for the first time this year.
Officials warn people to take extra care to prevent heatstroke since their bodies still haven't adapted to high temperatures this early in the year. Recommendations include using air conditioners appropriately and drinking water frequently.
The agency also says atmospheric conditions are extremely unstable in northern Japan. In the Amami region of Kagoshima Prefecture, rain clouds are developing due to warm, humid air flowing into the seasonal rain front.
Care should be taken about lightning strikes, wind gusts and tornadoes, sudden downpours, and hail. Firms required to take heatstroke prevention steps
Starting from June, businesses must take heatstroke prevention steps. This includes creating systems to detect workers suffering from heatstroke, offering first aid and cooling them down, and transporting them to hospitals immediately. Firms failing to do this will face penalties.
These measures come as scorching heatwaves have become fatal in recent years. Last year, 120 people died and more than 97,500 were taken to hospitals due to heatstroke. Seminar on workplace heatstroke prevention
In Tokyo, seminars taught businesses how to obey the new requirements. Firms rushed to take part.
Company managers were instructed to check in with their staff periodically and also to pair workers up - so any problems due to heat can be spotted, and taken care of, quickly. Cooling outfits popular
Work clothes equipped with cooling functions are increasingly popular. Ice Peltier vest
One item is cooling vests in which an aluminum plate, known as a Peltier device, has been embedded. These went on sale from late March and have become a huge hit, with more than 20,000 sold so far. Half of the sales are from businesses, especially in the construction sector.
T-shirts and jackets made from special fibers that use perspiration for cooling are also said to be selling well. Rainy season risk: food poisoning
The rainy season is also something people should be aware of. The risk of food poisoning rises as harmful bacteria and viruses grow rapidly amid high humidity.
Experts urge the most caution when temperatures rise to around 25 degrees Celsius on up to 40 degrees - levels at which harmful bacteria and viruses grow the fastest.
The Ministry of Health says there are three basic principles to prevent food poisoning.
The first is to prevent bacteria from sticking to food items.
People are advised to use different knives and cutting boards for different food items. Meat and fish should be the final things to be cut, an additional way of minimizing contamination risks.
Reusable shopping bags could also be a potential hazard.
Leakage from packed meat, poultry, or seafood items placed directly in the bag could cause contamination if harmful germs cling to the bag. These reusable bags should be washed or sanitized. Avoiding contamination
The second principle is heating foods thoroughly to kill bacteria. Experts say that if food and cooking equipment are heated at 80 degrees Celsius or higher for at least a minute, most of the bacteria that cause food poisoning will die.
The third principle is chilling food to prevent bacteria from multiplying. It is an ironclad rule to refrigerate food rather than leaving it at room temperature.
If you are planning to make bento lunchboxes and take them outside, it is important to let the food cool down before packing them - and to include ice packs for even more protection.