A heat dome moving from the Texas Panhandle into the Southwest is driving triple-digit temperatures across the West, with parts of California seeing 110–120 degrees and the region set for its hottest stretch of the year. The extreme heat intensifies wildfire activity and smoke, spreading north into the Northwest and into parts of Canada, while air quality deteriorates in several areas. Forecasters warn that dry air and strong high pressure will maintain dangerous conditions through the weekend and into August. Health officials emphasize recognizing heat-related illness and taking protective actions as the heat and smoke ramp up. The developing pattern suggests continued fire activity and degraded air quality across much of the western U.S. and adjoining regions in the near term.
Dive Deeper:
A heat dome is described as a persistent, high-pressure system that traps heat over a large area, amplifying temperatures and contributing to drought and wildfire danger.
Temperatures are forecast to range from 100–111 degrees in the Southwest, with lower-100s expected to expand into California's valleys and 110–120 degrees in southern California's deserts.
The Northwest, the Sierra, Great Basin, southern California mountains, and northern Rockies are highlighted as regions at elevated wildfire risk as the heat dome persists and winds pick up.
Wildfire smoke is expected to be most intense from the Northwest to the Dakotas and into the Northeast by August, with air quality concerns topping the forecast in the Northwest and localized smoke in other hot regions.
Many fires are described as lightning-caused, tied to recent North American monsoon activity, contributing to expanding fire crews and ongoing smoke dispersal.
Public health guidance notes signs of heat-related illness and urges protective measures as hot, humid conditions hinder the body's ability to regulate temperature.
Forecasters anticipate the current pattern to sustain high temperatures and wildfire activity into the coming weeks, potentially pushing smoke across broader parts of the U.S. and Canada.