More than 125 million Americans are on alert for sweltering heat from coast-to-coast, as heat alerts are in place from Southern California to the intermountain West and northern Plains, upper Midwest and across to the Northeast. 

Daily record highs may be broken in Rapid City, Fargo, Grand Forks in the northern Plains on Tuesday.

In the Northeast, record daily highs could be broken at Plattsburgh and Syracuse, New York. Other parts of New England may get with a degree or two of a daily record today. 

Those daily record highs would follow several broken on Monday, including in Bismarck, North Dakota, with 105 degrees F; International Falls, Minnesota, at 97; and Hibbing, Minnesota, at 93. Rapid City, South Dakota, and Dickinson, North Dakota, tied records with 102 and 103, respectively.

On Wednesday, daily record highs are possible around Grand Rapids, MI and Wilmington, Delaware. An extreme heat warning is in place through Thursday for Minneapolis, Minneapolis, with daily high heat index up to 100 possible. 

Other extreme heat warnings are in place from Utah to the upper peninsula of Michigan. 

In Utah, Salt Lake City is expected to reach near 100 on Tuesday. Fargo is under an extreme heat warnings for a heat index as high as 105.

The heat index for places like Calumet, Michigan, and Duluth, Minnesota, could reach near 100. 

Detroit, Michigan, is under a heat advisory for a heat index near 105.

The rest of the week will remain hot and humid across the upper Midwest with highs in the 90s and heat indices feeling even warmer. 

In the Northeast, a heat wave begins today, with 3 or more days of temperatures at or above 90 degrees for New York City, Philadelphia and D.C. Those high temperatures could last five days, through Saturday.  

A heat advisory is in place for at least Tuesday and Wednesday across much of the Northeast due to heat indices around 100 expected. The upper Northeast will be hottest today with a heat index of 100 to 104 from Rochester and Albany, New York, to Boston, Massachusetts. 

The area between New York City and D.C. will likely be the hottest on Wednesday, with heat indices near 100 in NYC and near 105 in D.C. 

Philadelphia, Pennsylvania, and Trenton, New Jersey, are under an extreme heat warning for heat indices up to 107 on Wednesday. 

Out West, southern California is under heat alerts through Thursday. 

Temps will reach 85 to 90 across the coastal valleys and up to 105 for the interior valleys through Tuesday. 

A heat advisory stretches up to San Jose, California, where temps will reach the mid to upper 90s on Tuesday. 

Wednesday and Thursday will be hotter, with temps in downtown Los Angeles reaching the middle to upper 90s and interior valleys reaching up to 110. 

Next week, temperatures look less extreme across America. 

Significant flood threat in Texas

For the next three days, there is a level 3 of 4 flood threat in place in South-Central Texas.

That warning came amid a very rare and dangerous setup. Everyone in the region should be on alert, especially those near rivers and low water crossings. But even areas that don’t normally flood must be alert. 

The greatest threat will lie across the Edwards Plateau into Hill Country and along the Rio Grande Valley between the Big Bend down toward Eagle Pass.

Rainfall rates each day could exceed 2″ per hour. 

Each day on Tuesday through Thursday could see 3″ to more than 7″ of rainfall over this area. 

Three-day totals over that region could top 15″ in some places. 

Severe weather threat in northern New England

Fueled by the extreme heat and humidity and a sinking cold front from Canada, severe storms capable of destructive winds of more than 70 mph, large hail large than ping pong balls, and a strong tornado or two will move over northern New England today. 

A level 3 of 5 risk is in place from northeast New York through northern Vermont, northern New Hampshire, and northern Maine on Tuesday afternoon and evening. It includes Burlington, Vermont; Plattsburgh, New York; Caribou, Maine; Colchester, Vermont; and Massena, New York. 

Storms are most likely after 4 p.m. ET and continuing into the night as the cold front sinks south.