Beyond the Thermometer: 5 Heat Metrics That Drive Better Decision-Making

The briefing outlines five key heat metrics—land surface temperature, air temperature, heat index, wet bulb globe temperature, and thermal comfort indices—detailing their specific uses and limitations. It argues that while traditional metrics are useful for regional analysis and safety limits, thermal comfort modeling is essential for understanding human-scale heat exposure and designing local interventions like shade and wind corridors. The document provides a framework for matching these metrics to goals such as protecting pedestrians, reducing energy use, or lowering citywide temperatures.

• Traditional heat metrics serve different analytical purposes: land surface temperature (LST) is used for scientific heat mapping and comparing city surfaces, while air temperature is ideal for analyzing and comparing temperatures across time.
• The heat index and wet bulb globe temperature (WBGT) are superior to air temperature alone for predicting how the human body reacts to weather and determining the safety of outdoor activities, as they account for humidity, sunlight, and wind speed.
• Thermal comfort indices provide the most detailed assessment of human heat exposure by calculating the cumulative effects of radiation, air temperature, wind, and humidity at very local scales, typically in radiuses between one and five meters.
• Different urban heat goals require specific metrics for effective implementation: air temperature is used to lower citywide temperatures and reduce ground-level ozone; thermal comfort indices are used to protect pedestrians and people in public spots; and heat index or WBGT are used to set safety limits for outdoor activities.
• Urban characteristics such as pavement and a lack of green space can increase warming by an additional 1 degree C (1.8 degrees F) beyond global temperature rises, disproportionately impacting the more than 4 billion people living in cities.

APA

World Resources Institute (2025). Beyond the Thermometer: 5 Heat Metrics That Drive Better Decision-Making. https://www.wri.org/insights/beyond-thermometer-measuring-heat

Chicago

World Resources Institute. Beyond the Thermometer: 5 Heat Metrics That Drive Better Decision-Making. 2025. https://www.wri.org/insights/beyond-thermometer-measuring-heat.

Wikipedia

{{cite report |author=World Resources Institute |title=Beyond the Thermometer: 5 Heat Metrics That Drive Better Decision-Making |date=17 March 2025 |url=https://www.wri.org/insights/beyond-thermometer-measuring-heat |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{worldresourcesinstitute2025beyond, author = {{World Resources Institute}}, title = {{Beyond the Thermometer: 5 Heat Metrics That Drive Better Decision-Making}}, institution = {World Resources Institute}, year = {2025}, month = mar, url = {https://www.wri.org/insights/beyond-thermometer-measuring-heat}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }