March 2026 was the fourth warmest on record

The chart shows the globe's monthly average temperature per decade from 1940-2019, and then by year for 2020-2025, with the 1.5 degrees Celsius threshold highlighted. Numerous months from mid-2023 onward reached or exceeded a warming level of 1.5 degrees Celsius above preindustrial temperatures. However, as a long term planetary average, that boundary has not yet been crossed.

All data are in degrees Celsius relative to the 1850-1900 average temperature. Three months in 2016 (including January) exceeded the 1.5 degrees C threshold, but those are not shown here because that year is averaged into the decade of the 2010s.
Chart: Chris Mooney, ReportEarth.substack.comSource: Copernicus Climate Change Service/ECMWFCreated with Datawrapper