2025 was recorded as an exceptionally hot year due to heat waves affecting many places throughout the world. Climate change has increased the number and intensity of heat waves, making Urban (especially dense, low green) cities more vulnerable than they have ever been in history.
Below is a list of top 10 cities hit by heatwaves in 2025 that were most heavily impacted by heat waves according to reported extreme temperatures, their duration, and their impact on the surrounding region.
1. Delhi, India
New Delhi is one of the hottest cities in history, and the heatwaves were relatively prolonged, with multiple occurrences of extreme temperatures exceeding safe levels. In addition, the high density of the population, along with the high level of pollution, contributed to the impact of heat on the city.
2. Karachi, Pakistan
The heat index in Karachi was extremely high due to the combination of extreme heat and high humidity, which made the felt temperature and the actual temperature in the area very uncomfortable to live under. The fact that Karachi is so close to the ocean increases the stress from the extreme heat on the people of Karachi.
3. Manila, Philippines
Manila experienced extreme heat conditions prior to the summer peak of the year and had unusually high temperatures occur very early in the summer.
4. Jakarta, Indonesia
Jakarta has also suffered through prolonged heat periods due to high population density and low levels of green space available for the public to use, thus the city has been unable to effectively cool down or to provide cooling sources to its citizens.
5. Madrid, Spain
Madrid recorded one of its hottest summers ever, with a sharp rise in days above 35°C. Southern Europe was among the hardest-hit regions overall.
6. Rome, Italy
In terms of heat during the extreme heat waves that swept across Italy, Rome had high rates of mortality associated with the extreme heat waves, as did many parts of Italy. The heat waves in Europe in 2025 resulted in thousands of deaths in Italy alone.
7. Athens, Greece
Athens experienced sustained high temperatures of over 40 degrees Celsius for very long periods of time, and extreme heat affecting Mediterranean cities has become much more common.
8. Phoenix, USA
For yet another year, Phoenix is one of the hottest metropolitan areas in the world with multiple occurrences of extreme heat and very high temperatures.
9. Mexico City, Mexico
Mexico City has been impacted by unusual and long-lasting heat waves resulting in damage to the local water supply, air quality, and public health.
10. Stockholm, Sweden
There have been unprecedented levels of heat in what have historically been some of the coldest locations in the world. In Stockholm, the city saw extended periods of temperature exceeding 30 degrees Celsius, the first time this has happened in that country.
Stay In The Loop
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Final Insight
The pattern from 2025 is clear:
- South Asia and South East Asia are facing extreme and long lasting heat
- Southern Europe has experienced record levels of heat causing health impacts
- Even Northern Europe, typically much cooler than the rest of Europe, has seen unusual and unprecedented levels of heat
Heat waves are becoming a global urban crisis. By 2025, they were affecting cities around the world, no longer limited to geographic locations historically characterised as warm.
FAQs
1. Which region was most affected by heatwaves in 2025?
South Asia, Southeast Asia, and Southern Europe were among the hardest hit.
2. Are heatwaves becoming more frequent?
Yes, climate change is making heatwaves more frequent and intense.
3. Why are cities more affected than rural areas?
Due to the urban heat island effect, where concrete and buildings trap heat.
4. Did cooler regions also face heatwaves?
Yes, countries like Sweden and Finland experienced unusual heat in 2025.
