Extreme heat in Japan should be considered the “new normal.”

The warning from Tomoyoshi Hirota, a professor of agricultural meteorology at Kyushu University’s graduate school, comes as the mercury recently hit an all-time high of 41.2 degrees in Hyogo Prefecture. Elsewhere, 39 degrees, a level practically unheard a decade or so ago, is becoming common.

Hirota called on producers to change their mindset and develop plant species that can thrive in sizzling temperatures. 

That will require adjusting the amount and timing of veggie fertilizer applications based on long-term weather forecasts and personal experience, he said.

The withering heat has taken a toll on poultry farms, where fowls are suffering from summer fatigue, as well as producers of fruit and vegetables.

The standard trading value for wholesalers has already surpassed the level for the same period two years ago when soaring prices were dubbed the “egg shock.”

The abnormal weather in areas where vegetables and fruit are traditionally grown has spurred calls for farmers to take a pre-emptive approach to their endeavors based on the assumption that excessive heat readings are here to stay.

At the Hotoku Nojo poultry yard in Omitama, Ibaraki Prefecture, where 200,000 hens lay around 170,000 eggs a day, cooling pads are utilized to help the birds cope. Even so, the mercury inside the henhouse can reach 30 degrees, well above the comfortable range of 20 to 25 degrees.

Hens are particularly vulnerable to high temperatures because they lack pores in their skin and cannot cool down by sweating.

“The hens are suffering and not eating as much,” said a worried Mitsuhiro Toyomura, president of the company that operates the poultry farm. “Our output has drastically plummeted, and eggs are getting smaller.”

The monthly average value of one kilogram of M-size eggs for the Tokyo area, which is released by JA Z-Tamago Co. to serve as an indicator of transaction prices, was 330 yen ($2.20) as of July 25. This figure is 10 yen higher than for the same period in 2023, when the index peaked at 350 yen due to the avian flu outbreak.

Higher prices have also been reported in Osaka, Nagoya and Fukuoka. 

The latest farm ministry survey on food prices found that a 10-egg carton averaged 299 yen at supermarkets across Japan, up more than 20 percent year on year.

Also contributing to prolonged high egg prices is the lingering effect of the avian flu epidemic last winter that led to 8.4 million chickens, or upward of 6 percent of the total stock in Japan, being culled.

That led to a drop in supply capacity, which, combined with heat issues affecting hens, delivered another blow to the industry.

“Eggs are significantly more expensive this year, whereas prices usually start declining around summer due to reduced seasonal demand,” Toyomura explained. “Given a possible further decrease in production related to the extreme heat, this trend may continue for some time.”

The recent heat wave is wreaking havoc not only in poultry farms but also in renowned production regions for tomatoes, peaches and other crops.

Farmers in Amakusa, Kumamoto Prefecture, found brown spots on the leaves of their cucumbers raised in greenhouses.

“Vegetables are unable to withstand the blazing heat, which leads to insect infestation,” said 38-year-old Ryuichi Masuda of the local JA Amakusa agricultural cooperative. “It will no longer be possible for us to harvest cucumbers in bulk this year.”

As for corn, Masuda said the shorter June rainy season meant that male and female flowering was not aligned this year. This led to sparse kernels, with the corn crop half of initial forecasts.

Regional farmers are expected to shift to cherry tomato cultivation from August. Kumamoto Prefecture accounts for 20 percent of the crop’s output nationwide, making it the country’s largest producer.

Masuda noted that a farmer in his neighborhood had lost all their tomato seedlings to the heat.

“Vegetable species in general are affected,” Masuda lamented. “It is as if the environment has completely transformed over the past few years.”

Keisuke Noda, 47, a farmer in the Minami-Alps of Yamanashi Prefecture in central Japan, is anxious about the quality of the peaches and other agricultural produce he raises.

“The insides of fruits may turn brown due to water core if the heat wave continues,” he said.

Plant varieties with a high sugar content are especially prone to water core.

In addition, skin discoloration caused by blinding sunlight is another issue that put consumers off.

Entering the peak harvest season for Kawanakajima Hakuto, a species dubbed the “king of peaches,” Noda prayed that the nation’s traditional “four-season climate will return to normal as in the past.”

A survey was conducted in late June by the operator of Tabe Choku, a website that directly delivers agricultural and fishery products to consumers. Of the producers registered on the site, 331 responded to the questionnaire.

Most respondents--96.7 percent--cited the “extreme heat” as common changes observed at their facilities.

A total of 58.0 percent pointed to “reduced harvests or fish hauls” as an effect, followed by 29.6 percent and 25.7 percent who noticed increased volumes of “below-industrial-standard products” and “defective produce,” respectively.

A separate farm ministry survey found that the average price of peaches at supermarkets nationwide was 1,757 yen per kilogram, a 200-yen increase from the same period the previous year.

Prices of tomatoes and cucumbers, typical summer vegetables, have also risen by more than 10 percent. Smaller quantities of tomatoes and cucumbers were shipped in July because they grew poorly due to temperature fluctuations and a succession of cloudy days.

(This article was written by Eiji Zakoda and Nobufumi Yamada.)