September

September 2025 was the 3rd warmest September on record behind 2023 and 2024. 2025 is likely to become the third warmest year on record. ENSO neutral persists with a likely transition to La Niña before the end of the year.

Globally, September 2023 was the warmest September since record-keeping began in 1850, breaking the previous record by a enormous margin. 2023 is virtually certain to become a record warm year, and likely to be 1.5 °C above preindustrial.

Globally, September 2022 was the 4th warmest September since record-keeping began in 1850. Due to ongoing La Niña conditions, 2022 is projected to be around the 4th or 5th warmest year overall.