Overview
- C3S reports January–November 2025 averaged about 1.48°C above the 1850–1900 baseline, placing this year virtually certain to finish second or third in the instrumental record.
- November 2025 was roughly 1.54°C above pre-industrial levels, the third-warmest November, with pronounced warmth over northern Canada and the Arctic Ocean.
- 2024 remains the hottest year on record at about 1.6°C above pre-industrial levels, and 2025 warmth persisted despite a weak La Niña.
- Extreme impacts this year included cyclones and floods across South and Southeast Asia that killed more than 1,600 people, Europe’s heat linked to an estimated 16,500 additional deaths, and Spain’s worst wildfires in three decades.
- Global fossil-fuel emissions hit a new high in 2025 as COP30 produced no decisive fossil-fuel phase-out, reinforcing UN assessments that the Paris 1.5°C goal is unlikely without much faster reductions.