There’s an old folk tale passed down in Katsuura, a sleepy city on the eastern edge of the Boso Peninsula known for its pristine beaches and 400-year-old morning market, where vendors sell fresh seafood as fishing boats return to the port.
According to the yarn, during one especially hot summer, a local kimono store owner named Gonzaemon asked his head clerk, Tasuke, to assemble a bag sewn together with 10 tatami’s worth of sheets of nori. He then asked Tasuke to hike up to Cape Hachiman and fill it with the wind blowing in from the Pacific Ocean.
Perplexed by the strange request, Tasuke obliged nonetheless. He gathered the gusts and hoisted back the bag that had expanded into a gigantic balloon. He was then asked to open the end of the sack that was tied shut and direct it toward his master — a cool breeze gushed out, offering some much needed respite from the intolerable heat.
“It's so refreshing. Oh, it feels good,” Gonzaemon exclaimed.
That cool wind Gonzaemon craved is what put the city in Chiba Prefecture in the spotlight this summer, when temperatures rose to record highs, boiling many parts of the Japanese archipelago and leading a panel of scientists working under the Meteorological Agency to describe the weather as “abnormal.”
Katsuura — around 90 minutes by express train from Tokyo — has never seen the mercury climb above 35 degrees Celsius, a benchmark the agency uses to describe “extremely hot” weather, since records began in the city in 1906. Tokyo, in contrast, has seen a record-breaking 22 “extremely hot” days so far this season, with daily highs only just dipping below 30 C, even though the weather typically cools in September.
While Japan’s climate and topography make it particularly vulnerable to natural disasters, the recent bouts of intense precipitation, heat and typhoons triggered by a variety of weather conditions amid the backdrop of global warming have resulted in soaring interest in regions with more temperate environments — a phenomenon that could have an impact on domestic migration trends as the world braces for a scorching “new normal” boosted by human-induced climate change.
“The number of consultations we receive from those interested in relocating to Katsuura has really gone up during the hot months,” says Kise Chiyura, an official in the city’s emigration and settlement support team.
Chiyura, a tanned 26-year-old who studied at a university in Katsuura, moved back to the seaside city in April last year after working for two years near Tokyo. “I didn’t appreciate it during my time in college, but now I realize how much cooler it is here. There are many days during the summer when I don't need to turn on the air conditioner at home.”
The 21st century is often described as the era of climate migration, with extreme weather events including heat waves, floods and wildfires — catastrophes that many nations have seen aplenty this year — prompting people to leave their homes. In its 2021 Groundswell report, the World Bank said that climate change could force 216 million people across six world regions to relocate within their countries by 2050.
While a climate-induced migratory shift may not yet have taken hold in Japan, reports have shown that among those interested in resettling elsewhere, regions with a temperate climate are consistently at the top of the list.
Furusato Kaiki Shien Center (roughly translated as the Hometown Return Support Center), a Tokyo-based nonprofit that offers support for people interested in moving to rural areas, received a record high 52,312 inquiries in 2022. The three most popular prefectures were Shizuoka, Nagano and Tochigi — all within relatively close proximity to Tokyo and all known for having cities that offer at least some relief from Japan’s sweltering summers.
“While we don’t factor it in our surveys, climate is definitely a component when people consider moving,” says Satomi Abe, a spokesperson for the organization. “Many Tokyoites thinking of relocating elsewhere look for areas with both an abundance of nature and good access to the capital.”
That trend could accelerate, as the effects of climate change began to be felt more acutely this summer. In particular, that came through an extended period of heat.
From July 16 to Aug. 23, 106 of the 915 monitoring stations nationwide set new records — or matched them — for the highest daily maximum temperatures.
A variety of weather conditions have been cited as contributing to the phenomenon: High-pressure systems covering the main island of Honshu — as well as typhoons bringing in warm air masses as they inched northward — caused temperatures to soar. Meanwhile, record-high sea surface temperatures, as well as westerlies flowing in higher latitudes than usual are considered to be behind the summerlong heat wave.
The big question, then, is whether Japan should brace for hotter summers in the years ahead.
The short answer? Yes.
The average temperature between June and August this year was 1.76 C higher than the 30-year average for 1991 to 2020, making it the hottest summer since record-keeping began in 1898. The Japan Meteorological Agency says average summer temperatures in the nation have been rising, albeit with various fluctuations, and are increasing at a rate of 1.25 C per 100 years.
“This summer was outstandingly hot,” says Hiroaki Kawase, a senior scientist at the Meteorological Research Institute and a member of the Meteorological Agency’s expert panel. And when examining the phenomenon through extreme event attribution, a field within meteorology that tries to measure how climate change impacts extreme weather, it’s evident that “without climate change, the events we experienced this summer would have been rarer.”
Keeping its cool
Several factors are behind Katsuura’s famously cool breeze.
“Around 10 kilometers off the coast of the city, the water depth plunges to 200 meters,” says Masayoshi Yoshino, an official at the city’s tourism department. And during summer, the southerly winds push away the warm water near the surface and stir up cold seawater from the deep ocean floor, which is believed to cool the winds that reach land, resulting in lower temperatures.
“It seems to be a phenomenon distinct to Katsuura. Other neighboring coastal municipalities are hotter,” he says.
Between 1991 and 2020, the average maximum daily temperature in July and August in Katsuura was 26.7 C and 29.0 C. This year, it was 28.9 C and 31.4 C in those months, compared with average highs of 33.9 C and 34.3 C in Tokyo.
It wasn’t until last summer, however, that the city of 16,000 suddenly found itself in the headlines, after Chiba-native and celebrity Matsuko Deluxe praised Katsuura’s cool summer climate on a television program.
“We’ve been receiving many inquiries since then,” Yoshino says.
In fact, the number of consultations from those interested in relocating to Katsuura reached 409 in fiscal 2022, which ran through March, compared with 75 in fiscal 2020. And this summer, there were 106 queries in July and August alone from those interested in moving to the coastal city, compared with just five during the same period in 2020.
It’s not only Katsuura that has come onto the radar of those wanting to escape scorching urban centers, whose human-made structures make them hotter than natural landscapes.
Summer resorts in Japan are typically located out in the countryside, often in high altitude areas. Among the most famous around Tokyo, for example, are the city of Karuizawa in Nagano Prefecture, as well as the Kiyosato Highlands in Yamanashi Prefecture and Nasu Highlands in Tochigi Prefecture.
Many of these more famous destinations, however, are often packed with expensive hotels and holiday homes, and are heaving with tourists during the high season. Instead, the trend now, it seems, is to seek out lesser-known, commutable areas close to urban centers.
Among them is Kitaibaraki, the northernmost city of Ibaraki Prefecture and bordering Fukushima Prefecture to the north and the Pacific Ocean to the east. Like Katsuura, the rather nondescript city shot to fame this summer due to its pleasant climate, catching local officials off guard.
“It seems a city resident contacted a television broadcaster running a show about cooler places and introduced Kitaibaraki,” says Noritoshi Matsukawa, a city official. “Yes, I suppose our city is rather cool compared with other areas in the prefecture, but we’ve never really publicized that aspect.”
Indeed, between 1991 and 2020, Kitaibaraki’s average maximum temperatures in July and August were 25.7 C and 27.4 C, respectively, while this year it was 29.3 C and 30.8 C.
Matsukawa says this is likely due to how a cold subarctic current known as oyashio flows along the coast of Kitaibaraki from the north, while cool winds blowing from the ocean hit the inland mountains, remaining in the city.
“We’ve been receiving many calls from people, especially those living in Tokyo, asking whether it’s really that cool in Kitaibaraki,” he says. “And yes, it is, to a certain extent, but I also do feel that it’s getting hotter here, too.”
Hard to leave
It’s still too early to tell if recent climate trends in Japan will translate to more significant migration patterns. The draw of cities like Tokyo remains strong as an aging and shrinking population accelerates rural depopulation and chips away at transportation and other essential infrastructure in the countryside.
As remote work spread during the pandemic, for example, the capital experienced its first net population outflow in 2021. That trend quickly reversed the following year, however, as the health crisis began to show signs of waning.
“When faced with a choice between a more temperate environment and the convenience of the city, I believe many will still choose the latter,” says Takaharu Niimi, a researcher at the Japan Research Institute and a certified weather forecaster. “But it’s definitely an effective sales pitch for municipalities looking to attract tourists and new residents.”
Hokkaido, for example, is known for its milder summer temperatures, especially in eastern coastal cities such as Kushiro and Nemuro that have been promoting their climates to attract newcomers. Still, other areas such as the prefectural capital Sapporo experienced record-breaking heat this year.
And even Katsuura, which prides itself on not seeing the mercury climb above 35 C, had a close call when the temperature reached 34.5 C in July.
“I’m sure officials were on edge,” Niimi says.
“But then again, if it becomes too hot, people can simply turn on their air conditioners,” he says, alluding to the fact that, with the exception of Hokkaido, air conditioners can be found in the vast majority of Japanese homes.
With electricity prices soaring, however, switching them on is becoming a luxury, especially for the elderly and economically vulnerable. And that’s leading to deadly consequences.
According to the Environment Ministry, an average of 1,145 people died of heatstroke annually between 2017 and 2021, up sharply from the 179 reported between 1996 and 2000. Over 80% were those 65 or older, and among those who died indoors, 90% either didn't own air conditioners or didn’t use them.
In that context, there is a clear appeal to cooler cities like Katsuura, whose pleasant winds inspired the story of the wind-filled bag made of nori.
Yunosuke Saito and his family moved to Katsuura from Tokyo in 2020, and now operates a burrito shop and campsite in the city called Black Rams.
“I like surfing, and was looking for an area close to the sea on the eastern side of the Boso Peninsula,” says the 38-year-old father of two.
“It’s definitely cooler here compared with Tokyo. It can get hot during the day, of course, but the wind is still refreshing,” he says.
Saito says that, according to locals, every 10 years or so Katsuura finds itself in the media for its relatively cool climate. But even still, “this summer was really hot,” he says.
“We didn’t get much rain, either. I do feel that global warming is playing a part.”