The loop below shows the large-scale flow changes that have brought a pleasurable return of more seasonable temperatures to Utah and the Intermountain West. Note in particular the westward shift of the upper-level ridge that was previously parked over northern Utah to the northeast Pacific.
Here's a closer look at the changes. On June 29, the upper-level ridge and the highest temperatures at 700 mb (roughly 10,000 feet, color contours) were parked directly over Salt Lake City, resulting in a high temperature of 104ºF. BTW, if you adjust that to sea level, you get a maximum of about 127ºF.
This morning, however, the upper-level ridge is thankfully over the north Pacific and our 700-mb temperatures are about 8ºC lower.
And, as a result, the National Weather Service forecast for the next few days is relatively pleasant.