Climate Shift Index Alert•June 25, 2024
Southern U.S. impacted by climate change-influenced heat
Cities across the southern U.S. continue to grapple with extreme heat as temperatures reach severe highs made at least five times more likely because of climate change.
Daily average temperatures are expected to reach Climate Shift Index (CSI) levels of 5 in cities across Texas, Alabama, Florida, Georgia, and North Carolina. Atlanta is expected to reach level 5 on both Tuesday, June 25, and Wednesday, June 26. A CSI level 5 indicates that human-caused climate change made this excessive heat at least 5 times more likely, signifying an exceptional climate change event.
Over the entire period, 52 million people in the southern U.S. will experience at least one day with CSI level 5.
From Tuesday, June 25, through Friday, June 28, a prolonged heat event ranging from “moderate” to “major” severity is anticipated to affect residents from Texas to the Carolinas.
Heat Advisories have been issued across the Gulf Coast from Texas and Louisiana, to Mississippi, Alabama, and the Florida Panhandle. Heat index values are projected to reach between 105°F and 112°F+ across 13 states.
A persistent and ongoing heat dome is forecasted to remain stationary over the southwestern United States, with anticipated high temperatures ranging from 100° and 105° in parts of the Desert Southwest.
Potential record-breaking heat is forecast for Tuesday, June 25 and Wednesday, June 26, across Georgia, including Atlanta, due to excessive heat conditions ahead of a stationary front. High temperatures are forecast to exceed 100°F, as much as 8°F to 10°F above average, through the weekend.
On Thursday, June 27, during the first presidential debate of the 2024 election, high temperatures are expected to be 5°F above average, reaching the mid-90s in Atlanta. Heat index values are forecast to climb as high as 102°F.
Many cities will experience extended periods of extreme heat. See table below for U.S. cities most impacted.
City | Date of peak temperature anomaly | Peak temperature anomaly (°F above normal) | Maximum temperature that day (°F) | CSI level that day | Days at or above CSI level 2, June 25-27 | Average CSI, June 25-27 |
|---|---|---|---|---|---|---|
Atlanta, GA | June 26 | 9.5 | 98.1 | 5 | 3 | 4.0 |
Raleigh, NC | June 26 | 7.8 | 98.9 | 5 | 2 | 2.3 |
Montgomery, AL | June 25 | 7.7 | 100.1 | 5 | 2 | 2.7 |
Mobile, AL | June 25 | 6.3 | 94.1 | 5 | 2 | 2.3 |
Miami, FL | June 27 | 3.1 | 90.4 | 5 | 3 | 3.0 |
Tampa, FL | June 27 | 2.8 | 87.2 | 5 | 3 | 4.3 |
Tallahassee, FL | June 25 | 5.4 | 95.1 | 4 | 2 | 2.3 |
Charlotte, NC | June 26 | 5.4 | 95.2 | 4 | 2 | 2.0 |
New Orleans, LA | June 25 | 5.3 | 92.7 | 4 | 2 | 2.0 |
Columbia, SC | June 25 | 4.9 | 96.2 | 3 | 2 | 1.7 |
Houston, TX | June 27 | 4.5 | 97.7 | 3 | 3 | 2.3 |
Baton Rouge, LA | June 25 | 3.7 | 93.2 | 3 | 2 | 1.7 |
Jacksonville, FL | June 25 | 2.4 | 95.5 | 3 | 3 | 2.3 |
What impact could this extreme heat have?
Exposure to this level of heat can trigger heat-related illnesses, including heat exhaustion and heat stroke, a life-threatening condition. Agricultural workers and others working outside will have higher exposure.
The National Weather Service’s HeatRisk scale forecasts parts of Florida’s heat-related impacts as “extreme.”
There is a higher mortality risk associated with heat waves that are more intense or longer, and which occur earlier in the summer.
Hot nighttime temperatures are highly correlated with heat-related mortality.
Cities in Georgia have opened cooling centers to combat the effects of excessive heat.
Use the Climate Shift Index global map to see CSI levels in your city and region, and see our FAQs to learn about the CSI in both English and Spanish.
What do experts say?
Dr. Andrew Pershing, vice president for science at Climate Central, said:
“Climate change has made the extreme heat that is pummeling the U.S. this summer much more likely and much more intense. This is an unnatural disaster that is directly linked to carbon pollution from coal, oil, and natural gas.”