Washington: An intense heatwave is sweeping across large parts of the United States and Canada, pushing temperatures above 40°C in several regions and breaking long-standing records.
In the US, Billings, Montana, reached 43.9°C, breaking the city’s previous all-time record of 42.2°C. Salt Lake City, Utah, recorded 42.8°C, surpassing its earlier record of 41.7°C.
Earlier this month, Newark, New Jersey, recorded 40.6°C, breaking a daily temperature record that had stood since 1966. Philadelphia also tied its daily record at 39.4°C, marking its hottest temperature in 15 years.
In Canada, Environment and Climate Change Canada confirmed Armstrong, Ontario, reached 40.8°C, setting a new local record. Other regions, including Sioux Lookout, Pickle Lake and Geraldton, also recorded their hottest temperatures for the date.
The US National Weather Service warned that dozens more daily temperature records could be tied or broken as the extreme heat continues across much of the country.
Meteorologists said the main cause behind the widespread heat is a massive heat dome. A heat dome forms when a large area of high atmospheric pressure settles over a region and remains nearly stationary.
The high-pressure system acts like a lid on a pot, preventing rising warm air from escaping and trapping hot air over the same area for several days. As the air slowly sinks, it becomes compressed and warmer. Limited cloud cover allows strong sunshine to heat the ground, while trapped air reduces cooling at night.
Nasa explained that the same high-pressure system pushes storm tracks away, reducing rainfall and allowing the ground to become drier. Dry soils absorb more heat instead of using energy to evaporate moisture, causing temperatures to rise further.
The heat is also worsening wildfire conditions across parts of Canada and the northern United States. Smoke from active fires in Ontario, Manitoba and other provinces has moved into the US Midwest and Northeast, leading to air quality alerts.
Health officials warned wildfire smoke particles can irritate lungs and worsen asthma, heart disease and respiratory conditions. Forecasters expect the heat dome to continue affecting parts of North America for several more days.
