Heat Storms

What are heat storms?

• Exceptionally large, prolonged, and widespread heat events that affect extensive geographical areas for weeks or months.
• Unlike an ordinary heatwave, which is generally limited to a particular region and period, heat storms can spread across multiple regions and occur repeatedly.
• Heat cascades occur when heat storms follow one another, overlap, or occur simultaneously, extending the period of extreme heat.
• Climate researchers use these terms to communicate the scale and persistence of extreme heat events. They are not established standard meteorological categories like the IMD's heatwave classification.

What causes heat storms?

• Global warming: Rising average temperatures increase the likelihood and intensity of extreme heat.
• Persistent atmospheric conditions: High-pressure systems can trap hot air over a region and suppress cloud formation and rainfall.
• Dry soil conditions: Reduced soil moisture limits evaporative cooling, allowing more incoming solar energy to heat the land.
• Climate variability: Phenomena such as El Niño can raise temperatures in several regions and intensify existing heat risks.
• Urbanisation: Concrete surfaces, reduced vegetation and waste heat from human activities intensify heat exposure in cities.

Why are heat storms a concern?

• Prolonged heat exposure increases the risk of heatstroke, dehydration, cardiovascular stress and kidney problems.
• Heat stress reduces crop yields, affects livestock and increases irrigation demand.
• Higher cooling demand increases electricity consumption and places pressure on power systems.
• Greater evaporation and prolonged dry conditions can worsen water shortages.
• Hot, dry vegetation creates conditions favourable for the spread of wildfires.
• Outdoor workers, particularly those in agriculture and construction, face reduced productivity and greater occupational risks.

Conclusion:

The growing scale and persistence of extreme heat require a shift from responding to individual heatwaves to planning for prolonged periods of extreme heat. Heat Action Plans, early-warning systems, climate-resilient infrastructure, urban green spaces and heat-health surveillance are essential to reduce the risks to lives and livelihoods.