Overview
- Global temperatures in 2025 were about 1.43°C above the 1850–1900 average, ranking second or third warmest on record with a slight La Niña cooling compared with 2024.
- For the first time the WMO made Earth’s energy imbalance a core indicator, confirming a new high in 2025 and showing that roughly 91% of excess heat goes into the oceans, 5% into land, 3% melts ice and about 1% warms the atmosphere.
- Ocean heat content set a record for the ninth straight year and the rate of ocean warming more than doubled from 1960–2005 to 2005–2025, with most of the ocean surface experiencing at least one marine heatwave in 2025.
- Atmospheric carbon dioxide is at its highest level in roughly 2 million years and methane and nitrous oxide are at least 800,000‑year highs, with the largest annual CO2 increase recorded in 2024 and levels continuing to rise in 2025.
- Extreme heat, fires, floods, droughts and storms caused thousands of deaths and multi‑billion‑dollar losses in 2025, including more than $60 billion from California wildfires, while the WMO notes a possible El Niño later in 2026 that could lift temperatures again in 2027.