Western Japan Faces Intense Heatwave as Temperatures Exceed 35°C

The western region of Japan is experiencing an unprecedented heatwave, with temperatures in cities like Osaka and Kyoto surpassing 35°C (95°F) in late June, according to the Japan Meteorological Agency (JMA). This extreme weather has prompted local governments to issue health advisories and adjust workplace policies, including recommendations for more casual attire.

On June 24, the JMA recorded a high of 36.8°C (98.2°F) in Osaka, marking one of the earliest and most severe heat events in the region’s history. The agency warned that the heatwave, driven by a persistent high-pressure system over the Pacific, could last through mid-July, with temperatures remaining above 30°C (86°F) for at least two weeks.

Extreme Heat Impacts Western Japan

The heatwave has disrupted daily life across western Japan, particularly in Osaka, Kyoto, and Hyogo prefectures. The JMA reported that 42 prefectures, including Osaka, have issued “heat illness prevention advisories,” urging residents to avoid outdoor activities between 10 a.m. and 4 p.m. and to stay hydrated.

Local hospitals in Osaka have seen a 20% increase in heat-related emergency visits compared to the same period last year, according to the Osaka Prefectural Government. The Tokyo Metropolitan Government’s Health Department has also issued guidelines for businesses, emphasizing the importance of air conditioning and regular breaks for employees.

“This is the most intense heatwave we’ve seen in decades,” said Hiroshi Tanaka, a meteorologist with the JMA. “The combination of high temperatures and humidity is creating dangerous conditions, especially for the elderly and those with preexisting health conditions.”

Tokyo Officials Adjust Work Attire

In response to the heat, the Tokyo Metropolitan Government has advised public sector employees to adopt more casual dress codes, including wearing shorts and light clothing. While not a formal mandate, the guidance reflects a broader shift in workplace policies across Japan to prioritize employee well-being during extreme weather.

A spokesperson for the Tokyo Metropolitan Government stated, “We are encouraging staff to wear breathable, lightweight clothing to stay comfortable and safe. However, we emphasize that professional standards must still be maintained.”

This policy aligns with similar measures taken by other Japanese cities. For example, the Kyoto City Government announced in late June that it would allow employees to work in “summer uniforms” from June 20 to September 30. The Osaka Prefectural Government has also relaxed dress codes for public workers, though it has not explicitly endorsed shorts.

Health and Safety Concerns

Heat-related illnesses, including heat exhaustion and heatstroke, have become a major concern. The Japanese Ministry of Health, Labour and Welfare reported 1,200 heatstroke cases in June, with 12 confirmed deaths. Many of the victims were elderly individuals who were unable to access air-conditioned spaces.

To mitigate risks, local governments have opened cooling centers in public buildings. In Osaka, 200 such facilities are now operational, offering air-conditioned spaces, water, and medical assistance. The city has also launched a public awareness campaign, distributing leaflets with tips for staying cool and hydrated.

“We are urging residents to check on vulnerable neighbors, especially the elderly, and to use cooling centers if needed,” said Osaka Mayor Hirofumi Yoshimura. “This heatwave is a serious threat, and we must act collectively to protect our communities.”

Comparison to Past Heatwaves

This year’s heatwave bears similarities to the 2018 “Super Heatwave,” which caused over 1,000 deaths nationwide. However, experts note that the current event is occurring earlier in the year, raising concerns about its duration and intensity. The 2018 heatwave, which peaked in July, was linked to a record-breaking high of 41.1°C (106°F) in Kumagaya, Saitama Prefecture.

“The timing of this heatwave is unusual,” said Dr. Yukihiro Okada, a climate scientist at Kyoto University. “Typically, Japan’s peak heat occurs in July and August, but the early onset suggests a shift in weather patterns, possibly linked to climate change.”

Climate models predict that extreme heat events in Japan will become more frequent and severe in the coming decades. The JMA has warned that the country could see temperatures exceeding 40°C (104°F) in the next 50 years, necessitating long-term adaptations in urban planning, healthcare, and workplace policies.

What’s Next for Western Japan?

The JMA has forecasted that the heatwave will persist through mid-July, with temperatures gradually declining in August. However, the agency has also warned of potential “heat island effects” in densely populated areas, where concrete and asphalt retain heat and exacerbate conditions.

Local governments are preparing for extended hot weather by expanding cooling center networks and increasing public outreach. The Tokyo Metropolitan Government has also announced plans to install additional air-conditioned spaces in public transportation hubs, including train stations and bus terminals.

For residents, the immediate priority is to stay informed about weather updates and follow health guidelines. The JMA recommends checking local weather forecasts, using sunscreen, and avoiding outdoor exertion during peak heat hours. Those with access to air conditioning are advised to keep it running, even at night, to maintain cooler indoor temperatures.

How to Stay Safe During the Heatwave

1. Hydrate regularly: Drink water even if you don’t feel thirsty, and avoid alcohol and caffeine.
2. Limit outdoor activity: Schedule outdoor tasks for early morning or late evening when temperatures are cooler.
3. Use cooling centers: Many cities have public facilities offering air-conditioned spaces.
4. Check on neighbors: Ensure elderly or vulnerable individuals have access to cooling resources.
5. Monitor weather alerts: Follow updates from the JMA and local authorities for real-time guidance.

The current heatwave serves as a stark reminder of the growing challenges posed by climate change. As temperatures continue to rise, Japan’s approach to extreme weather will likely evolve, with greater emphasis on resilience, adaptation, and public health initiatives.

For the latest updates on the heatwave, visit the Japan Meteorological Agency website or follow local government announcements.