September

October 2025 was the 3rd warmest October on record behind 2023 and 2024. 2025 is likely to become the third warmest year on record. Transition to La Niña with a likely return to Neutral this winter.

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.