July: United States Sets New Record For Overnight Warmth With 63.6 Degrees

The United States in July set a record for overnight warmth, providing little relief from the day’s sizzling heat for people, animals, plants and the electric grid, meteorologists said.

The average low temperature for the Lower 48 states in July was 63.6 degrees (17.6 Celsius), which beat the previous record set in 2011 by a few hundredths of a degree.

The mark is not only the hottest nightly average for July, but for any month in 128 years of record keeping, said National Oceanic and Atmospheric Administration climatologist Karin Gleason.

July’s nighttime low was more than 3 degrees (1.7 Celsius) warmer than the 20th century average.

Scientists have long talked about nighttime temperatures — reflected in increasingly hotter minimum readings that usually occur after sunset and before sunrise — being crucial to health.