July 2021 was Earth’s hottest July since global record-keeping began in 1880, 0.93 degrees Celsius (1.67°F) above the 20th-century average, NOAA’s
National Centers for Environmental Information, NCEI, reported August 13. Since July is also the hottest month of the seasonal cycle, that meant that July 2021 was “more likely than not the warmest month on record for the globe since 1880,” NOAA said. July 2021 was just 0.01 degree Celsius hotter than July of 2016, 2019, and 2020, so these months can be considered to be in a statistical tie for Earth’s hottest month on record.
The record July warmth is particularly remarkable since there was a moderate La Niña event in the Eastern Pacific that peaked in November 2020 and ended in May 2021. La Niña events typically cause global cooling of about 0.1 degree Celsius; the peak cooling occurs
five months after the La Niña peak, on average. July 2021 temperatures would have been even warmer had a La Niña event not occurred earlier this year.