The U.S. National Oceanic and Atmospheric Administration said Thursday that July was 0.95 degrees Celsius (1.71 degrees Fahrenheit) warmer than the 20th century average for the month.
Because July is generally the warmest month on the calendar, meteorologists say this means it also set a new all-time monthly record for the past 140 years.
Last month's temperatures narrowly topped the previous July record, set in 2016, by 0.03 C (0.05 F).
The results had been expected after several European countries including France, Belgium and Germany reported that July smashed previous national temperature records. The Swedish hamlet of Markusvinsa recorded a sizzling 34.8 C (94.6 F), the highest temperature measured north of the Arctic Circle.
According to NOAA's records, 9 of the 10 hottest Julys on record have occurred since 2005 and last month was the 43rd consecutive July above the 20th century average.
Record temperatures have gone hand-in-hand with other climate extremes. Warming oceans have led to an early melt of sea ice in the Bering Strait between Russia and Alaska, said Rick Thoman, a climate specialist at the University of Alaska Fairbanks.
June of this year had already set a sizzling record for that month over the past 140 years.
The year to date is also 0.95 C (1.71 F) above the long-term average, but still slightly behind 2016, NOAA said.