Heat Storms: How Reuters Data Journalists Quantified Extreme Heat

Reuters data journalists Maurice Tam and Ben Welsh explain how they developed a uniform definition for heat waves and identified larger, longer-lasting phenomena they call heat storms. The conversation covers the methodology behind the analysis, the scale of change since the 1960s, and the decision to name individual storms. It also examines reported impacts in Texas and the Amazon and outlines planned follow-up reporting.

■ Definitions and methodology
- Challenge of no universal heat-wave definition
- Five-day top-10% threshold and heat-storm size criterion

■ Findings since the 1960s
- Increase in active heat storms and continuous global presence after 2008
- Growth in storm size and duration

■ Naming and communication
- Rationale for naming storms to define boundaries and lifespan
- Use of named storms in explanatory narratives

■ Reported impacts and next reporting
- Texas football heat illness case and Amazon dolphin deaths
- Planned coverage of health, mortality and ecological consequences

Viewers interested in climate data journalism, extreme-heat measurement and science communication will find a concise account of how a reporting team translated global climate data into a public-facing frame. The episode focuses on Reuters’ methodology and selected reporting examples rather than offering a comprehensive scientific or policy assessment. It provides context for interpreting heat-wave coverage and for following the series’ later reporting.