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Monday, Aug 10, 2026

Are heat domes becoming more common in North America?

Cassis Tingley, The Colorado Sun
yes

The number of heat domes in North America has increased every year since 1940, a recent climatology study found.

The rise in heat domes corresponds with an increase in extreme heat due to human-caused climate change, the study found. A heat dome is a large, warm, high-pressure air mass that traps hot air and suppresses precipitation for several days to over a week. The number of heat domes in northwestern North America is projected to nearly double by 2080 if carbon emissions continue at high levels. 

A heat dome parked over the Western U.S. in July led to record highs in several states, with temperatures peaking at 115 degrees in Miles City, Montana.

Extreme heat increases the risk of heat-related illness. 2026 has seen the highest rates of medical visits for heat-related illnesses in Colorado since the state started collecting data in 2019.

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