Climate Shift Index Alert•May 13, 2024
Dangerous, early-season heat in Florida made five times more likely by climate change
Florida is poised to experience a period of unusually hot conditions made more than five times more likely by human-caused climate change.
Over the next several days, especially between May 14-16, much of Florida will experience temperatures above 90°F. The intensity of the heat and humidity and the fact that this is arriving early in the season makes this event especially dangerous. Human-caused climate change has made these conditions more than five times more likely.
Note: This event may continue beyond May 16. Use the Global Climate Shift Index map to stay updated on heat in your region.
How unusual is the forecasted heat?
Daytime temperatures are expected to exceed 90°F across Florida this week. This forecast extreme heat will be combined with high humidity, leading to dangerous heat index values between 100°F and 105°F.
Overnight low temperatures will run 5°-10°F above average. Record nighttime warmth is possible in metropolitan areas in South Florida. Low temperatures near or above 80°F are expected in Miami, Fort Lauderdale, and Naples.
Heat advisories could be issued for the first time in 2024 in South Florida.
Many cities will experience extended periods of extreme heat. See table below for the 11 cities most impacted.
How has climate change influenced this heat?
Daily average temperatures are expected to reach Climate Shift Index (CSI) levels of 5 in Central and Southern Florida. A CSI level 5 indicates that human-caused climate change made this excessive heat at least five times more likely, signifying an exceptional climate change event.
Over the entire period, 17 million people in Florida will experience at least one day with CSI level 5.
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.
City | Date of peak temperature anomaly | Forecast peak temperature anomaly (°F above normal) | Forecast high temperature that day (°F) | Forecast days at or above CSI 3 [May 14-16] | Forecast average CSI [May 14-16] |
|---|---|---|---|---|---|
Fort Myers | Mayo 15 | 5.2° | 91.4° | 3 | 5 |
Gainesville | Mayo 15 | 3.7° | 89.6° | 1 | 2 |
Jacksonville | Mayo 15 | 6.8° | 90.8° | 1 | 2 |
Miami | Mayo 15 | 11.4° | 93.1° | 3 | 5 |
Orlando | Mayo 15 | 12.4° | 97.8° | 3 | 5 |
Panama City | Mayo 15 | 2.2° | 81.2° | 0 | 0 |
Pensacola | Mayo 15 | 6.5° | 89.4° | 0 | 1 |
Sarasota | Mayo 15 | 3.8° | 90.5° | 3 | 5 |
Tallahassee | Mayo 15 | 1.8° | 86.8° | 0 | 0 |
Tampa | Mayo 15 | 3.5° | 89.1° | 3 | 5 |
West Palm Beach | Mayo 15 | 10.3° | 90.1° | 3 | 5 |
What impact could this extreme heat have?
Exposure to this sort 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 this heat at a category 2 (moderate) to 4 (extreme) for much of the state throughout this time frame. Level 4 (extreme) heat, with little to no overnight relief, will affect anyone without effective cooling and/or adequate hydration, including healthy adults.
Hot nighttime temperatures are highly correlated with heat-related mortality.
This event is intense, persistent (likely beyond the three days considered here), and occurs early in the season. This combination results in a higher mortality risk.
What do experts say?
Dr. Andrew Pershing, VP of Science at Climate Central, said:
“Heat is the deadliest weather event. Human-caused climate change has made the intense early-season heat hitting Florida much more likely.”
How do we know climate change is influencing this heat?
The Climate Shift Index uses peer-reviewed methodology to estimate how climate change has increased the likelihood of a particular daily temperature. It can be run using historical or forecast temperatures.
Using computer models, we compared the likelihood that these temperatures would occur in a world without carbon emissions released by humans, versus in today's world with decades of carbon emissions building up in the atmosphere. This is an established scientific method to determine how much climate change has or has not affected individual extreme weather events.
For this analysis, temperatures come from the National Center for Environmental Prediction’s Global Forecast System.
To request an interview with a Climate Central scientist, please contact Peter Girard at pgirard@climatecentral.org
Reporting resources
Until greenhouse gas emissions end, heatwaves everywhere will continue to become hotter and more dangerous. Explore quick facts and local analyses on the links between climate change and extreme heat in:
Climate Central’s Extreme Weather Toolkit: Extreme Heat
World Weather Attribution’s guide to reporting on extreme heat and climate change
Yale Climate Connections’ summary of the connection between heat waves and climate change.