July 12 (UPI) — A major heat dome expanded from the interior West into the Upper Midwest on Sunday on its way to smothering the East later this week, forecasters said.

The heat in the East is expected to be shorter and less intense than the early July heat wave, but parts of the West are coming within a few degrees of all-time record highs.

Dangerous heat is also gripping even the Desert Southwest, where communities are used to extreme temperatures. The pattern will raise the risk of heat exhaustion, heatstroke and heat-related deaths.

Motorists are urged to carry plenty of water with them in the event of a breakdown.

Temperatures climbed well above 100 degrees Fahrenheit across much of the Great Basin, the Cascades and Sierras east to the western Rockies, eastern Washington, eastern Oregon, Nevada, Idaho, Utah, western Colorado and northern Arizona this weekend.

The building heat dome has already pushed season-high temperatures into the 110s in Phoenix, Las Vegas and Palm Springs, Calif.

The heat expanded north this weekend, bringing highs of 106 in Salt Lake City, 107 in Bismarck, N.D., and 110 in Billings, Mont. Those temperatures are 10-25 degrees above historical averages during what is typically the hottest part of the year.

As the heat shifts east into the north-central United States early this week, some daily record highs will be challenged. As the hot air spreads east of the Rockies into more humid air, AccuWeather RealFeel Temperatures will run as much as 10-15 degrees higher than the actual air temperature.

While the North American monsoon will begin to temper the heat across parts of the West with increasing clouds and thunderstorms, multiple days of 90-degree heat are forecast across the Midwest, including Minneapolis, Chicago, Detroit and Cleveland.

Minneapolis and Chicago can expect at least four consecutive days with highs at or above 90.

“Temperatures will peak in the mid- to upper 90s in the Interstate 95 cities of the mid-Atlantic and New England during the heat surge this week,” AccuWeather Vice President of Forecast Operations Dan DePodwin said. “While high temperatures will still create dangerous conditions, the heat will be somewhat less intense and shorter-lived than the early July heat wave.”

Humidity levels with the heat in the Midwest and Northeast this week will be significantly lower when compared to the week of Independence Day.