If you haven't noticed, it's summer. And it's scorching hot.
Excessive heat warnings or advisories have been issued for at least 15 states as another heat wave continues to smother the Midwest, mid-Atlantic and Northeast.
According to the National Weather Service, temperatures will be 10-15 degrees above normal from Chicago to Boston, with dangerous heat index values exceeding 100 degrees through at least Wednesday.
"Breath-stealing heat" in Philadelphia will make it feel well over 100 degrees, the Philadelphia Inquirer said. A Bermuda High will push temperatures in the City of Brotherly Love to 99 degrees.
[Slideshow: Beating the heat]
In Chicago, highs could reach 100 degrees with a heat index of 110 degrees, the weather service said. (If it reaches 101, it would break the 100-degree mark set in 1942.)
In Ann Arbor, Mich., the high temperature is expected to range anywhere from 98 to 105 degrees; in Detroit, where the forecast high is 102, six schools were closed on Tuesday due to lack of air conditioning.
In Washington, D.C., temperatures could reach 100 degrees for the sixth time this year, and a heat index of 105 is expected on Wednesday. (Hopefully, the intense heat won't melt the tarmac at Reagan National this time.)
In New Jersey, which has already seen 16 days of temperatures of higher than 90 degrees this summer—the heat index will hit 101.
There is, however, some relief on the way. Tuesday "will be the peak of the hot temperatures in the Great Lakes and Northeast," according to the Weather Channel. "The heat and humidity will continue into Wednesday along the Northeast I-95 corridor from New York to Washington."
[First Person: Destructive Nevada heat, drought hurt our small farm]
The first half of 2012 was officially the hottest ever recorded, according to the National Oceanic and Atmospheric Administration. The average temperature was 52.9 degrees Fahrenheit, or 4.5 degrees above average, the NOAA said on Monday. Twenty-eight states east of the Rockies set temperature records for the six-month period. The 12-month period ending June 30 was the warmest 12-month period of any on record, according to the NOAA.
Record-breaking temperatures blistered most of the United States in June, with more than 170 all-time temperature records broken or tied during the month.
Heat is the No. 1 weather-related killer in the United States, claiming more lives each year than floods, lightning, tornadoes and hurricanes combined, according to the weather service. A heat wave that began late last month and stretched into July was blamed for at least 30 deaths.