July was hottest month ever on record, NASA and NOAA say

Data from both agencies showed that July was hotter than any other month in global temperature records. Last month, millions of Americans were under severe heat advisories. 

"NASA data confirms what billions around the world literally felt: temperatures in July 2023 made it the hottest month on record, NASA Administrator Bill Nelson said in a statement. "In every corner of the country, Americans are right now experiencing firsthand the effects of the climate crisis, underscoring the urgency of President Biden’s historic climate agenda. The science is clear. We must act now to protect our communities and planet; it’s the only one we have.”

According to NASA, July 2023 was 0.43 degrees Fahrenheit hotter than any other July in the agency's record, which dates back to 1880. The five hottest Julys in NASA's record have all happened in the last five years. 

NOAA's global climate report indicates that the global surface temperature in July was 2.02 degrees Fahrenheit above average, placing it as the hottest July in the agency's 174-year-old database. 

Since July is typically the hottest month of the year, NOAA says it's likely that last month was the hottest month on record.

“This July was not just warmer than any previous July – it was the warmest month in our record, which goes back to 1880,” NASA's Goddard Institute for Space Studies Director Gavin Schmidt said. “The science is clear this isn’t normal. Alarming warming around the world is driven primarily by human-caused greenhouse gas emissions. And that rise in average temperatures is fueling dangerous extreme heat that people are experiencing here at home and worldwide.”

July also was the fourth-consecutive month where global ocean surface temperatures reached a record high, according to NOAA's monthly climate report. 

Earlier this month, the European climate agency Copernicus reported that July was one-third of a degree Celsius (six-tenths of a degree Fahrenheit) hotter than the old record.  Normally global temperature records are broken by hundredths or a tenth of a degree, so this margin is unusual.

The Associated Press contributed to this report.