The heat wave wilting much of the nation will hit metro Denver and most of Colorado again Tuesday, bringing sizzling temperatures under sunny blue skies — with a chance of afternoon thunderstorms but only light, brief rain, according to the National Weather Service.

The high temperature in Denver will be 99 degrees, decreasing at night to 66 degrees, weather service forecasters said. On Wednesday, the high temperature is expected to be 94 degrees.

Meteorologists estimated the likelihood of rain at 30%.

Later this week through Saturday, temperatures are expected to hit 93 degrees or higher, forecasters said.

Any thunderstorms forming over the mountains and foothills Tuesday will spread across metro Denver and the urban Interstate 25 corridor in the late afternoon and evening, forecasters said. These may kick out wind gusts at speeds up to 50 miles per hour and lightning but probably not heavy rain.

On Colorado’s eastern plains and around Grand Junction, exceptional heat is expected with temperatures exceeding 100 degrees, forecasters said.

The weather service issued a heat advisory covering the central mountains near Salida and Canon City and southeastern Colorado, effective through 8 p.m., warning of dangerous heat and advising residents to stay cool, indoors if necessary, drinking plenty of water.

The high temperatures in Colorado ranked relatively cool compared with other parts of the Southwest, such as Phoenix, where highs have topped 110 degrees for nearly a month and night temperatures haven’t dropped below 90 degrees. On Tuesday, about 45 million people in a dozen states from California to Florida and as far north as Montana were living under weather service heat alerts.