Extreme heat conditions are impacting various regions across Utah, with temperatures reaching triple digits in St. George, Moab, and Wendover. The National Weather Service is using its HeatRisk service to help residents assess the potential for heat-related health impacts and infrastructure stress as temperatures remain elevated through the end of August.
Regional Temperature Forecasts
According to a forecast from the National Weather Service Salt Lake City, temperatures in St. George are expected to reach 107 degrees on Wednesday, August 26, with highs remaining at 106 degrees on Thursday, August 27. In the Moab area, highs are forecasted at 100 degrees on Wednesday and 102 degrees on Thursday. Wendover is also expected to see significant warmth, with temperatures reaching 96 degrees on Wednesday and 97 degrees on Thursday.
Understanding HeatRisk Categories
The National Weather Service uses an experimental HeatRisk service to place upcoming temperature forecasts into climatological context. This service identifies heat events that may lead to increased heat-related impacts by dividing risk into five distinct categories. The system uses specific colors to help the public quickly identify the level of concern for their specific situation.
HeatRisk Risk Levels
The HeatRisk scale ranges from a value of 0 to 4. A value of 0, represented by the color green, indicates little to no risk and requires no preventative action. A value of 1, represented by yellow, indicates a minor risk primarily for extremely heat-sensitive groups, such as those outdoors without effective cooling or hydration. In these cases, the National Weather Service recommends increasing hydration and reducing time spent outdoors during the strongest sun.
Moderate Heat Risk Impacts
A HeatRisk value of 2, represented by orange, indicates a moderate risk. This level primarily affects heat-sensitive groups and those without effective cooling, such as air conditioning, though some risk exists for the general population exposed to the sun for long periods. At this level, the National Weather Service notes that some transportation and utilities sectors may face issues, and health systems may see an increase in emergency room visits.
Major Heat Risk Dangers
As risk levels increase, the potential for danger expands to a broader population. A HeatRisk value of 3, represented by red, signifies a major risk to all individuals who are active in the sun or belong to a heat-sensitive group. During these events, living spaces without air conditioning can become deadly during the afternoon and evening, as fans and open windows may not be adequate. This level of heat is associated with uncommon conditions in most locations and may lead to power interruptions due to increased electrical demands.
Extreme Heat and Infrastructure Risk
The highest level, a value of 4 represented by magenta, indicates an extreme risk to the entire population. This level is rare in most locations and occurs up to a few times a year in southern regions like the Desert Southwest. Extreme heat events of this magnitude are often multi-day events that can be deadly for those without proper hydration or cooling. The National Weather Service warns that poor air quality is likely and power outages are increasingly likely as electrical demands reach critical levels. During such events, residents are encouraged to check on neighbors and stay in cool locations, including overnight.
Previous Weather Advisories
In addition to the HeatRisk assessment, the National Weather Service provides specific advisories for high-risk areas. A previous Heat Advisory for the Great Salt Lake Desert, Mountains, Tooele and Rush Valleys, and the Salt Lake Valley was issued earlier in the month, though the National Weather Service Salt Lake City reported that the threat from that specific advisory ended at 7 a.m. MDT on Saturday, August 22, 2026.
