Executive summary
World Weather Attribution’s year-end review of 2025 paints a consistent picture: extreme weather is occurring at concerning levels, with human-driven warming amplifying heat, drought and fire conditions, heavy rainfall and storm impacts across regions. Even with La Niña conditions, global temperatures remained high and the real-world consequences were clear. The report also highlights two credibility-critical points for risk practitioners: impacts are strongly shaped by local vulnerability and inequality, and the evidence base is uneven, with data gaps limiting confidence in some Global South analyses.
What happened (in 2025)
Rather than analysing a single event, this publication is World Weather Attribution’s annual synthesis. It reviews major extreme weather events studied during 2025 across hazard types including heatwaves, floods and extreme rainfall, storms, drought and wildfire. Across the events analysed, the authors document widespread human impacts alongside severe economic, agricultural and infrastructure losses.
What the attribution review found
The 2025 synthesis highlights five risk-relevant findings.
High global temperatures amplified multiple hazards, intensifying prolonged heatwaves, worsening drought and fire weather, and increasing extreme rainfall and wind associated with storms and floods.
Today’s impacts are already material at current warming levels. At roughly 1.3 °C of human-caused warming, climate change is acting as a present-day risk driver rather than a future-only concern.
Small increases in global temperature have produced large changes in extremes. Warming since 2015 has translated into measurable increases in extreme heat frequency, including additional very hot days each year on average.
Vulnerability and inequality strongly shape outcomes. Disproportionate impacts are observed among marginalised groups, including gender-specific exposure and livelihood impacts during extreme heat.
There are limits to both adaptation and evidence. While preparedness can reduce harm, intense storms and extremes can still cause severe losses, particularly in highly exposed regions. In parallel, data and modelling gaps limit confidence for some heavy-rainfall analyses in parts of the Global South.
How climate attribution fits into weather risk reporting
Climate attribution does not predict events; it explains how the likelihood or intensity of events has changed due to human-caused climate change. In a synthesis year like 2025, its value lies in revealing consistent risk signals across multiple events while also highlighting where uncertainty remains.
Why this matters for organisations
Historical baselines are becoming less reliable, vulnerability strongly influences outcomes, and adaptation reduces but does not eliminate risk. Together, these factors reinforce the need for forward-looking weather risk assessment rather than reliance on historic norms.
How to use this in your own risk work
Organisations should stress-test assets and operations against present-day climate conditions, document uncertainty transparently, and prioritise vulnerability reduction while planning for residual risk.
Source
World Weather Attribution (2025). Unequal evidence and impacts, limits to adaptation: Extreme Weather in 2025, published 29 December 2025.
https://www.worldweatherattribution.org/unequal-evidence-and-impacts-limits-to-adaptation-extreme-weather-in-2025/