Los Angeles, California - A "widespread and significant" heat wave is predicted to bring oppressive temperatures to drought-hit western states over the weekend, with all-time records at risk of falling, the National Weather Service said Friday.
A developing heat dome will spread from the Pacific Northwest through the Rocky Mountains into the northern plains, where temperatures could hit 110 degrees Fahrenheit on Sunday.
"Extremely hot daytime highs combined with potentially record-warm overnight lows will result in increasing heat stress, leading to widespread major to locally extreme HeatRisk," the agency said.
"Extreme" is the highest level on the NWS's HeatRisk scale, with impacts affecting anyone without cooling or hydration. Energy grids are also expected to come under strain.
Hot and windy conditions will bring elevated wildfire conditions, with much of the western US already experiencing abnormally dry to drought conditions.
A National Interagency Fire Center prediction map showed the states of Washington, Oregon, Idaho, Montana and Wyoming at particularly elevated risk.
The latest heat wave follows similar events that roasted the central and eastern US last week, and Europe before that.
Scientists from the World Weather Attribution group released an analysis showing the hot and humid conditions that characterized the past US hot spell – which fell as the country celebrated its 250th anniversary – would have been "virtually impossible" without human-caused climate change.