On August 29, 1948 almost the entire country was over 90F, and there were 100 degree temperatures from coast to coast.
California 119,Arizona 115
North Carolina 106, Utah 106, Georgia 104, Nebraska 104, Nevada 104, South Dakota 104, South Carolina 103, Wyoming 103, Alabama 101, Kentucky 101, New Mexico 101, Idaho 100, Louisiana 100, Mississippi 100, Montana 100, Pennsylvania 100, Tennessee 100, Virginia 100, West Virginia 100
Delaware 99, Illinois 99, Iowa 99, Kansas 99, Maryland 99, Texas 99, Colorado 98, Indiana 98, Missouri 98, New Jersey 98, New York 98, Ohio 98, Oklahoma 98, Arkansas 97, Florida 97, Oregon 97, New Hampshire 96, Michigan 95, Rhode Island 95, Wisconsin 95, Maine 94, Massachusetts 94, Minnesota 92, North Dakota 92, Washington 91