Heat dome set to break records in Rockies and Plains before moving eastward
A high-pressure system will drive triple-digit temperatures across the northern Rockies and Plains this weekend, with heat and humidity expected to spread to the Midwest and East early next week.
A persistent heat dome is forecast to push record-high temperatures into the northern Rockies and Northern Plains beginning this weekend. Extreme heat watches and warnings have already been issued from Nevada to parts of the Dakotas and northern Minnesota, signaling conditions that could cause heat-related illnesses.
Temperatures in Utah, Idaho, Wyoming, Colorado, Montana and the Dakotas are expected to reach the triple-digit range through Monday, and some locations on the northern High Plains could top 110 °F. Morning lows in larger cities may remain above 70 °F, limiting nighttime relief. A modest cooling trend may arrive for some areas from Tuesday to Thursday.
The heat could challenge all-time records. Salt Lake City may approach its historic high of 107 °F, while Billings, Montana, could see its first 110 °F reading in 92 years of records. Nearly two dozen sites in eastern Montana and Wyoming are also projected to near or exceed their historical peaks.
The upper Midwest, especially Minnesota, will feel the heat first, with the hot, humid air mass moving through the rest of the region by Monday and reaching the Eastern United States by Tuesday. Afternoon temperatures are expected to climb into the 90s, and some Mid-Atlantic and Midwest locations could near 100 °F mid-week. Morning lows may stay in the upper 70s, offering little relief.
Forecasters anticipate a strong cold front from eastern Canada to move into the Northeast Tuesday-Wednesday, potentially bringing cooler air to the Great Lakes and New England later in the week, though it may also trigger severe thunderstorms with damaging winds ahead of the front.
"An extreme heat watch is issued when conditions are favorable for an extreme heat event that could lead to heat-related illnesses, including heat exhaustion and heat stroke, within the next 24 to 48 hours," the National Weather Service explained.
Residents without air conditioning are advised to locate cooling shelters or stay with friends or family who have climate-controlled environments.