A cool front will move across the Upper Midwest, cooling the region slightly while the Plains remain seasonally hot. Some scattered rain showers are possible in Minnesota and Wisconsin from this front.
Further south, scattered showers and thunderstorms will develop in the Southeast, keeping humidity and heat index values high. The southern half of the country has experienced a long-lasting heat wave that has pushed temperatures above 100 degrees for many days in some areas. Meanwhile, Texas has endured an epic drought with no signs of easing.
In the West, monsoon moisture will creep into the desert Southwest, triggering scattered showers and afternoon thunderstorms. Some of these thunderstorms will spread into southern California, bearing high humidity that will keep overnight low temperatures uncomfortable for parts of the state's Central Valley.
Temperatures in the Northeast will rise into the 80s and 90s, while the Southeast and Plains will see readings in the 90s and 100s. The Southwest's temperatures will rise into the 90s and 100s, while the Northwest will witness 80s and 90s. Temperatures in the lower 48 states ranged Saturday from a morning low of 32 degrees at West Yellowstone, Mont. to a high of 104 degrees at Cushing, Okla.
Weather Underground: http://www.wunderground.com
National Weather Service: http://iwin.nws.noaa.gov