Introduction 1

Key messages 2

Greenhouse gas concentrations reached record observed levels in 2025 4

Earth’s energy imbalance is increasing 5

Ocean heat content in 2025 was the highest on record 6

Global mean sea level reached a record high in 2026 7

Global temperature for January–September 2026 was 1.47 °C ± 0.13 °C above the pre-industrial average 8

El Niño: From observations and monitoring to early warnings and action 9

Climate change and variability shape different regional realities 11

Sea-ice extent remained mostly below average in both polar regions 12

Precipitation varied around the world f rom January to August 2026 13

Extreme weather and climate-related events f rom January to August 2026 had major global impacts. 14

Earth’s glaciers lost more than 400 gigatons in 2025, equivalent to approximately 1 mm of sea-level rise 15

Water stored on land – in groundwater, soil, rivers, reservoirs, glaciers and snow – has declined globally since 2014 16

Climate variability continued to impact renewable energy production 17

Health impacts of weather and climate extremes span people, communities and health systems – but so do solutions 18

Agriculture and food security are under pressure f rom weather and climate extremes 19

Early warning systems are expanding with improved observations and forecasting 20

Acknowledgements and data sources 21