Each of the past 12 months has broken temperature records

At the time, June 2023 did not seem like a special month. It was the warmest June on record temperature recordHowever, monthly records are not actually unusual during a period in which the 10 warmest years on record have all occurred in the past 15 years. And monthly records typically occur in years without exceptions; At that time, the warmest July on record occurred in 2019, a year that did not stand out much compared to the rest of the past decade.

But July 2023 set another monthly record, easily eclipsing the high temperatures of 2019. Then August set another monthly record. And so has every month since—a streak of records pushing 2023 to be the warmest year since tracking began.

On Wednesday, the European Union’s Earth watchdog, Copernicus, announced that it’s now been a full year where every month has been the warmest version of that month because there are enough tools to track global temperatures.

Monthly temperature history shows how extreme temperatures have been over the past year.Courtesy of C3S/ECMWF

As you can see from this chart, most years have a mix of temperatures – some above average, some lower. Peak months especially tend to cluster, but those clusters also tend to be shorter than the year as a whole.

In the Copernicus data, a similar year-long streak occurred before, in 2015/2016. NASA, which uses slightly different data and methods, did not show similar performance in the earlier period. NASA has not yet released May’s temperature results – which are expected in the next few days – but there’s a good chance the results will also show a year-long record.

In addition to the records, the EU is highlighting the fact that the one-year period ending in May was 1.63 degrees Celsius higher than the average temperature for the period 1850–1900, which is used as a baseline for temperature pre-industrial level. That’s notable because many countries have ostensibly pledged to try to keep temperatures below 1.5 degrees Celsius above pre-industrial conditions by the end of the century. While it’s likely that temperatures will drop below the target again at some point within the next few years, new records show that we have a very limited window of time before temperatures Continuously exceed goals.

For the first time in history, temperatures were kept stable at over 1.5 degrees Celsius above the pre-industrial average.Courtesy of C3S/ECMWF