Oppressive and dangerous heat is set to continue across large portions of the U.S., as more hot, muggy and hazy conditions linger. 

Heat advisories have been issued from northern Texas to parts of southern Illinois and Indiana, and then eastward to the Carolinas. 

Some of the hottest cities will include Kansas City, St. Louis, Louisville and Memphis. 

Temperatures will range from the 90s to the low 100s, but will feel even more uncomfortable when combined with high humidity values.

HOUSE IN NORTH CAROLINA SET ABLAZE BY LIGHTNING STRIKE: REPORTS

Southern heat index

Expansive heat in the South  (Credit: Fox News)

Heat indexes will soar to 110-115 degrees. 

Overnight lows will fall into only the 80s, while the remaining humidity will provide little relief. 

Southern heat index

Expansive heat in the South  (Credit: Fox News)

Heavy rain and storms are expected across several parts of the country. 

BONNIE STRENGTHENS INTO MAJOR HURRICANE OFF OF MEXICO

Southern heat dew points

Southern dew points  (Credit: Fox News)

A frontal boundary extending from the northern Plains to the mid-Atlantic will bring some severe afternoon storms. 

The storms will bring frequent lightning and damaging winds. 

Severe storm threats in the US

The threat of severe storms across the U.S. (Credit: Fox News)

CLICK HERE TO GET THE FOX NEWS APP

Additionally, moist air will mean some heavy downpours, bringing a chance for flash flooding.