A widespread, major heat wave spread from the Plains to the East during the week leading up to and through the Fourth of July weekend. It brought both oppressive humidity and blistering highs that broke records in parts of the mid-Atlantic and Northeast states.

Through July Fourth, over 165 million Americans in the Midwest and East had been at risk of either "major" or "extreme" heat-related health issues, according to the National Weather Service experimental HeatRisk product.

Many experienced triple-digit heat indices, with daily low temperatures that didn't drop below the mid-80s for some, offering little relief at night.

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(MAPS: 10-Day US forecast highs, lows)

(MORE: 5 things to know to stay safe in a heat wave)

Records have fallen

Some all-time heat records were tied or broken as well as numerous daily records broken.

On June 30, La Crosse, Wisconsin's low temperature was only 81 degrees, tying it with four other dates for the city's all-time warmest low dating to 1872. That most recently happened on July 4, 2012.

Various other record warm lows for the date were set June 30 in Rockford, Illinois (77); Des Moines, IA (78); Louisville, Kentucky (79); and Topeka, Kansas (79).

Daily high temperatures were tied or broken on July 1 in Roanoke, Virginia (100); Cleveland, Ohio (97); Toledo, OH (99); Washington-Dulles (97); Syracuse, New York (96); Montpelier, Vermont (92); Caribou, Maine (90); and Mount Pocono, Pennsylvania (90).

Daily low temperature records fell on July 1 in Chicago-O'Hare (80); Madison, Wisconsin (79); Flint, Michigan (78); Buffalo, New York (75); and Fort Wayne, Indiana (74), among some others.

July 2 saw more than 20 record highs. A few of the most notable are: Newark (104), Philadelphia (103), Washington, D.C. (102), Boston (101), Atlantic City (103), Wilmington (101), New York City's Central Park (100).

New York City's Central Park reached 100 degrees Thursday, their first triple-digit high in almost 14 years (July 18, 2012).

Caribou, Maine, saw their low only drop to 71 degrees, which tied their all-time warmest low temperature. This has only happened a handful of times since 1939.

Numerous records also fell on July 3. Some notable ones include Atlantic City, New Jersey (105); Williamsport, Pennsylvania (100); Baltimore Inner Harbor, Maryland (103); Washington National D.C. (102); Raleigh, North Carolina (101); Nashville, Tennessee (101); Norfolk, Virginia (99); Providence, Rhode Island (98); Elkins, West Virginia (94); and Mansfield, Ohio (94).
July Fourth saw quite a few daily record highs as well, including Washington, D.C. (103); Baltimore, Maryland (102); Georgetown, Delaware (102); Raleigh, North Carolina (103); Norfolk, Virginia (100); Salisbury, Maryland (102); Lynchburg, Virginia (101); New Bern, North Carolina (97); Fayetteville, North Carolina (100); and Charlottesville, Virgina (101).

Atlantic City, New Jersey reached 106 degrees, breaking their all-time record high temperature.