While Chicago temps will have a mid-week rise in temps before a major cool-down by the weekend, a heat wave is building in Southern California and the U.S. Desert Southwest.
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Heat Building in Southwest to Major and Extreme Risks
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Southern California Heat Outlook
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Experimental Heat Risk Map
The NWS HeatRisk is an experimental 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 action at levels that may be below current NWS heat product levels:
![](https://wgntv.com/wp-content/uploads/sites/5/2024/09/STheatRiskMap.gif?strip=1)
Courtesy National Weather Service