Triple-digit temperatures are expected across the northern Plains, with dangerous heat pushing eastward into parts of the Mid-Atlantic.

"The planet's strongest heat dome will develop over the Intermountain West and Plains into next week," meteorologists Ben Noll wrote on X, adding, "This will produce rare levels of heat up to around 110 degrees in Idaho, Wyoming, Montana and the Dakotas. On Sunday, Billings, Montana, could be hotter than Phoenix!"

Meteorologist Jeff Berardelli also sounded the alarm, saying, "Whopper of a heat dome coming, and that's no exaggeration! In all aspects: size, longevity, and especially intensity this will be extreme. The heat dome should shatter all-time records for upper level pressure in the Northern Plain States." 

Bloomberg data for the Lower 48 show that forecast high temperatures will be comparable to those recorded during the last heat wave from late June into early July.

High temperatures in Washington are expected to reach 100F by midweek.