Japan hits new heat record with temperature reaching 107.24 degrees Fahrenheit
In recent years, Japan, South Korea, and Vietnam have been experiencing unusually high temperatures and prolonged heat events, significantly impacting local weather patterns and agriculture.
Japan
Last week, Japan recorded its hottest day in history with temperatures reaching 41.8°C (107.2°F) in early August 2025. This heatwave has been unusually long and intense, with experts warning about the health effects on vulnerable populations. Regions like Hiroshima show a worsening climate severity score in 2025 compared to the last 15 years, indicating an overall trend of increasing heat and associated climate strain. Nagano shows a moderate severity score, but recent weather patterns still indicate frequent warm and patchy rain days.
Tokyo is also experiencing extreme heat, and Mount Fuji's snowcap was absent for the longest recorded period last year, not appearing until early November. Blistering heatwaves have also hit Japan, with the summer of 2021 being the joint hottest on record, equalling 2023. The autumn of 2021 was the warmest since records began 126 years ago.
South Korea
South Korea is facing a stretch of unprecedented 22 consecutive “tropical nights”, where nighttime temperatures fail to drop below 25°C (77°F), prolonging stress on populations and energy systems. August 2025 forecasts predict the heat extending into September, raising concerns about the sustainability of water and power resources, as well as public health.
Vietnam
Though less detailed in the search results, Vietnam—falling within Southeast Asia's tropical climate zone—is also very likely experiencing increased heat stress, given the regional climate change trends affecting East Asia and Asia-Pacific. These changes typically include hotter temperatures, enhanced humidity, and more erratic rainfall, all of which pose serious risks to agriculture by reducing crop yields and stressing water resources.
Impacts on Local Weather Patterns
The heatwaves are accompanied by sustained high humidity in these regions, leading to extended warm nights and increased heat stress. Rainfall patterns are becoming less predictable, with some areas experiencing patchy rains instead of steady precipitation, affecting soil moisture levels critical for crops.
Impacts on Agriculture
Prolonged heat and tropical nights reduce crop productivity by increasing water demand and heat stress on plants, particularly rice, fruits, and vegetables common in these countries. Heatwaves can damage the quality of produce and lead to higher irrigation needs, straining local water supplies. Erratic rainfall and extended droughts or floods—common under climate change—disrupt planting and harvesting schedules, leading to economic losses in rural farming communities.
Overall, the 2025 East Asian heatwave represents an intensification of climate change impacts, with Japan and South Korea recording some of the hottest and longest heat events on record, while Vietnam and surrounding regions confront increased climate variability, presenting critical challenges for weather stability and agriculture sustainability in these countries.
- In contrast to the detailed data available for Japan and South Korea, Vietnam's tropical climate is also likely to experience increased heat stress due to regional climate change trends, which include hotter temperatures, higher humidity, and more erratic rainfall, posing risks to agriculture.
- Simultaneously experiencing enhanced heat stress and unpredictable rainfall patterns, environmental scientists are closely monitoring the impacts of climate change on weather patterns and agriculture within affected regions, such as Japan, South Korea, and Vietnam.
- Warning signs for climate change are evident in weather forecasting data, as prolonged heat events coupled with tropical nights challenge agricultural productivity across East Asian countries, straining resources and threatening rural economies.
