New Delhi: Extreme heat is increasingly affecting the world on a scale that goes beyond short periods of unusually high temperatures. These prolonged events can last for months, cover vast areas and cause serious consequences for people, agriculture and natural ecosystems.
A special investigation published by Reuters on October 20 identified these events as “heat storms”, referring to exceptionally large and long-lasting heat waves. The analysis examined hourly temperature data from more than one million grid squares worldwide, covering the period since 1960. Researchers also consulted two dozen meteorologists and climate scientists.
The findings indicate that extreme heat events have become substantially more frequent and widespread. Climate change and successive El Niño episodes are among the factors contributing to this growing threat.
What Are Heat Storms? How Frequently Do They Occur?
According to Reuters’ methodology, a heat wave is defined as a period of at least five consecutive days with abnormally high temperatures. A heat wave is classified as a heat storm when it covers at least 1% of Earth’s surface at its peak.
The analysis found a significant increase in the annual frequency of these events. During the 1960s, the world experienced an average of around five heat storms each year. In the current decade, the average has risen to approximately 102 annually.
One of the most extensive events identified was Vera, which lasted 367 days during 2023–2024. Over its lifetime, it affected nearly 85% of the planet. At its peak on January 5, 2024, the heat storm covered 31.3% of Earth’s surface.
The effects were felt across several regions. During the annual Hajj pilgrimage, temperatures at Mecca’s Grand Mosque reached 51.8°C, and more than 1,300 pilgrims died amid the extreme heat. In Greece, soaring temperatures contributed to devastating wildfires. In the Philippines, intense heat made school conditions difficult for students in buildings with limited air conditioning.
Heat Storms Put Agriculture and Livelihoods at Risk
The effects of prolonged extreme heat extend beyond immediate threats to human health. Agriculture and food production can also suffer when high temperatures combine with drought.
In Ivory Coast, extended heat and dry conditions damaged cocoa production. In Spain, drought associated with extreme heat events contributed to poor olive harvests and a sharp rise in olive oil prices.
These examples illustrate how prolonged hot weather can affect agricultural output, disrupt supply and create financial pressure for producers and consumers.
Heat Storm Raimundo Surpasses Vera’s Peak Coverage Record
The investigation found that the threat continued into 2026 with another major event, named Raimundo. It began on February 28 and affected nearly three-quarters of the planet during its lifetime.
On August 28, Raimundo covered 33.8% of Earth’s surface at its peak. This exceeded Vera’s record for the largest area affected by a heat storm at a single point in time.
Raimundo also brought intense heat to parts of Europe, contributing to major wildfires in Spain and France.
The investigation further found that both Vera and Raimundo passed over a melting glacier in Nepal before it collapsed on August 26, an event followed by catastrophic flooding. Initial indications suggest that rising temperatures may have contributed to the collapse, although its precise causes require further assessment.
Extreme Cold Events Are Also Becoming Less Widespread
Alongside the increase in extreme heat, the analysis identified a substantial reduction in the area affected by extreme cold. According to Reuters’ findings, the portion of the planet experiencing cold snaps or cold storms on an average winter day has declined by nearly 80% since the 1960s.
Taken together, the findings point to major changes in the world’s temperature patterns, with increasingly extensive heat events and a sharp reduction in the reach of extreme cold. The effects extend across public health, agriculture, ecosystems and communities exposed to prolonged periods of high temperatures.
Disclaimer: This article is based on the information provided from the Reuters investigation and is intended for general informational purposes. Climate findings and estimates reflect the methodology and data described in the report. Readers should consult the original investigation and relevant scientific research for further details.