Global Heat Waves Reach Unprecedented Levels

This summer’s heat waves are now being described as a “new normal” by climate scientists, as cities from Los Angeles to New Delhi record temperatures more than four degrees above historical averages.

Residents across Europe and Asia endured prolonged heat indices above 100°F, straining power grids and prompting emergency declarations by government agencies. Hospitals reported increases in heat-related illnesses, particularly among the elderly.

New satellite data show Earth’s surface temperature thresholds were broken multiple times in May — a month that historically experiences lower extremes.

Record-breaking global temperature anomalies recorded in May 2025.

Cities without adequate cooling infrastructure were hit hardest, particularly low-income neighborhoods and older populations lacking access to air conditioning or green spaces.

“It’s no longer enough to adapt,” said Dr. Lina Sorensen, a climatologist at the University of Copenhagen. “We must rethink urban design and human resilience in a warming world.”