Heat dome set to break records across Rockies, Plains and move eastward

A high-pressure heat dome is expected to drive record-high temperatures across the northern Rockies and Northern Plains beginning this weekend, before moving eastward to the Midwest and East later in the week. Extreme heat watches and warnings now extend from Nevada to Wisconsin, including parts of the Dakotas and northern Minnesota.

Temperatures in Utah, Idaho, Wyoming, Colorado, Montana and the Dakotas are forecast to reach the upper 90s and occasionally exceed 100 °F through Monday, with morning lows in some cities remaining above 70 °F. Salt Lake City could approach its all-time high of 107 °F, while Billings, Montana, may record its first 110 °F temperature in 92 years of records.

The upper Midwest is slated to feel the heat first, especially Minnesota, with the hot, humid air mass spreading across the region by Monday and reaching the East Coast by Tuesday. Afternoon highs in many Mid-Atlantic and Northeastern locations could near 100 °F, and nighttime lows may stay in the upper 70s, limiting relief.

Forecasters anticipate a cold front from eastern Canada to arrive Tuesday-Wednesday, potentially easing temperatures in the Great Lakes and New England areas by mid-week, though it may also trigger severe thunderstorms with damaging winds.

"An extreme heat watch is issued when conditions are favorable for an extreme heat event that could lead to heat-related illnesses within the next 24 to 48 hours," a National Weather Service statement read.

Authorities advise suspending major outdoor activities when warnings are in effect and recommend that those without air conditioning seek cooling shelters or stay with friends or family who have climate control.