May

May 2026 was the 2nd warmest May on record. El Niño has returned and is expected to rapidly strength. There is a ~2.5% chance that 2026 becomes a record warm year, but higher odds of a record annual average in 2027 following El Niño.

Globally, May 2023 was the 3rd warmest May since record-keeping began in 1850. A return of El Niño is ongoing, and 2023 is now slightly more likely than not to become a record warm year.