Understanding the global landscape of heat early warning systems

This report provides a global overview Heat Early Warning Systems, examining where they exist, how they are designed and operated, and their challenges and opportunities. It assesses the state of systems through the four core pillars of early warning systems and enabling components, drawing on peer-reviewed and non-academic evidence.

The report also presents ten recommendations to strengthen them. Priorities include embedding inclusive, community-led approaches; improving heat risk understanding across sectors; refining heat metrics and thresholds; and ensuring warnings lead to timely, coordinated actions through national and local Heat Action Plans. The report highlights the need for stronger governance, sustainable financing, and continuous learning. As climate change intensifies extreme heat, more robust and widely implemented systems will be critical to reducing preventable deaths, protecting livelihoods, and safeguarding essential services globally.