NWS HeatRisk Prototype
Identifying Potential Heat Risks in the Seven Day Forecast
Click map for potential heat risks and NWS forecast for a location.
The NWS HeatRisk Prototype is a color-numeric-based index that provides a forecast risk of heat-related impacts to occur over a 24-hour period. HeatRisk takes into consideration:
  • How unusual the heat is for the time of the year
  • The duration of the heat including both daytime and nighttime temperatures
  • If those temperatures pose an elevated risk of heat-related impacts based on data from the CDC
This index is supplementary to official NWS heat products and is meant to provide risk guidance for those decision makers and heat-sensitive populations who need to take actions at levels that may be below current NWS heat product levels.
Category Risk of Heat-Related Impacts
Green
0
Little to no risk from expected heat.
Yellow
1
Minor - This level of heat affects primarily those individuals extremely sensitive to heat, especially when outdoors without effective cooling and/or adequate hydration.
Orange
2
Moderate - This level of heat affects most individuals sensitive to heat, especially those without effective cooling and/or adequate hydration. Impacts possible in some health systems and in heat-sensitive industries.
Red
3
Major - This level of heat affects anyone without effective cooling and/or adequate hydration. Impacts likely in some health systems, heat-sensitive industries and infrastructure.
Magenta
4
Extreme - This level of rare and/or long-duration extreme heat with little to no overnight relief affects anyone without effective cooling and/or adequate hydration. Impacts likely in most health systems, heat-sensitive industries and infrastructure.
HeatRisk 0-Little to None 1-Minor 2-Moderate 3-Major 4-Extreme
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