Hundreds of weather stations recorded a new daily record for heat last Tuesday during a heat wave in the Midwest and eastern United States.Related video above: How do sports teams play safely in the heat?The heat wave was caused by a “heat dome,” which is when a “large, persistent area of high-pressure forces the jet stream northward and traps heat close to the ground in areas under the high pressure,” according to the National Oceanic and Atmospheric Administration. NOAA also described it as like putting a lid on a pot.Data for the entire United States was downloaded by the Hearst Television Data Team from the Southeast Regional Climate Center and was filtered to only include stations with a record-keeping period 30 years or longer. This is the period of record NOAA uses in its own analysis.A daily heat record is when the maximum temperature recorded for a day is the highest it has ever been for that specific calendar date. For example, June 24, 2025, was the hottest June 24 on record for 224 stations. On Monday, 165 stations recorded the highest maximum temperature on record. Daily maximum temperature records that were tied were not included.View the map below to see where daily heat records were broken in the United States. PHNjcmlwdCB0eXBlPSJ0ZXh0L2phdmFzY3JpcHQiPiFmdW5jdGlvbigpeyJ1c2Ugc3RyaWN0Ijt3aW5kb3cuYWRkRXZlbnRMaXN0ZW5lcigibWVzc2FnZSIsKGZ1bmN0aW9uKGUpe2lmKHZvaWQgMCE9PWUuZGF0YVsiZGF0YXdyYXBwZXItaGVpZ2h0Il0pe3ZhciB0PWRvY3VtZW50LnF1ZXJ5U2VsZWN0b3JBbGwoImlmcmFtZSIpO2Zvcih2YXIgYSBpbiBlLmRhdGFbImRhdGF3cmFwcGVyLWhlaWdodCJdKWZvcih2YXIgcj0wO3I8dC5sZW5ndGg7cisrKXtpZih0W3JdLmNvbnRlbnRXaW5kb3c9PT1lLnNvdXJjZSl0W3JdLnN0eWxlLmhlaWdodD1lLmRhdGFbImRhdGF3cmFwcGVyLWhlaWdodCJdW2FdKyJweCJ9fX0pKX0oKTs8L3NjcmlwdD4=
WASHINGTON — Hundreds of weather stations recorded a new daily record for heat last Tuesday during a heat wave in the Midwest and eastern United States.
Related video above: How do sports teams play safely in the heat?
The heat wave was caused by a “,” which is when a “large, persistent area of high-pressure forces the jet stream northward and traps heat close to the ground in areas under the high pressure,” according to the National Oceanic and Atmospheric Administration. NOAA also described it as like putting a lid on a pot.
Data for the entire United States was downloaded by the Hearst Television Data Team from the and was filtered to only include stations with a record-keeping period 30 years or longer. This is the period of record NOAA uses in its own analysis.
A daily heat record is when the maximum temperature recorded for a day is the highest it has ever been for that specific calendar date. For example, June 24, 2025, was the hottest June 24 on record for 224 stations. On Monday, 165 stations recorded the highest maximum temperature on record.
Daily maximum temperature records that were tied were not included.
View the map below to see where daily heat records were broken in the United States.
