Florida heatwave: Excessive heat warning, heat advisory, heat index today
Florida heatwave: What's the heat index for Orlando?
Orlando and Central Florida are under an Extreme Heat Warning and a Heat Advisory until 7 p.m. Tuesday night. FOX 35 meteorologist Noah Bergren looks at the current temperature, the heat index, how hot it got in Orlando, and how long the above-average heat is expected to stick around.
ORLANDO, Fla. - The Florida heatwave continues as a massive so-called "heat dome" brings dangerously hot temperatures to Orlando and Central Florida, and the rest of the Sunshine state.
An extreme heat warning has been issued for Volusia, Lake, Orange, Seminole, and Osceola counties until 7 p.m. Tuesday due to the dangerous heat index (real temperatures and humidity), which could reach 110 to 115. A heat advisory has been issued until 7 p.m. Wednesday for Volusia, Lake, Orange, Osceola, and Seminole counties, indicating heat index values between 108 and 112.
The dangerous heat could lead to heat-related illnesses, such as heat exhaustion or heat stroke.
What is a heat dome?
A heat dome happens when a large area of high-pressure traps hot air over a stretch of hundreds of miles, similar to a lid on a pot. Air sinks with high pressure overhead, and air dries out as it sinks. Drier air heats up more quickly than moist. With little to no moisture, it helps prevent clouds from forming too, allowing the sun to keep heating up the ground. This pattern is typically persistent as the high pressure is strong.
As a result, other weather systems that would normally help bring cooler and wet weather aren't able to move in. Consecutive dry days cause temperatures to build day after day, heating things up even more.
Extreme heat warning vs. heat advisory
What's the difference between an extreme heat watch and an extreme heat warning, and what should you do? Here's an explainer graphic from the National Weather Center.
An extreme heat warning is issued when an area experiences "extremely dangerous heat." People should avoid outside activities and direct sunlight and find ways to stay cool.
An extreme heat watch is when dangerous heat is possible. A heat advisory is issued when there is "dangerous heat" conditions, but it doesn't quite rise to the level of a complete extreme heat warning, per National Weather Service.
An extreme heat warning is issued when an area experiences "extremely dangerous heat,"
How hot did it get in Orlando? What was the heat index today?
Florida heatwave: What's the heat index for Orlando?
Orlando and Central Florida are under an Extreme Heat Warning and a Heat Advisory until 7 p.m. Tuesday night. FOX 35 meteorologist Noah Bergren looks at the current temperature, the heat index, how hot it got in Orlando, and how long the above-average heat is expected to stick around.
Daily heat records set - July 29, 2025
Three cities set or tied daily heat records on Tuesday, July 29:
- Sanford: 100 degrees, breaking old record of 98 set in 2010
- Leesburg: 99 degrees today, breaking old record of 97 set in 1987 and 2020
- Daytona Beach: 98 degrees today, tying record set in 1992
Orlando (MCO) reached 98 degrees on Tuesday, one degree shy of the 99-degree record set in 1949. Melbourne reached 95 degrees, 3 degrees below the 98-degree record set in 1999.
What's the all-time heat record for Orlando?
According to the National Weather Service, the hottest temperature ever recorded in Orlando (since records were kept) was 103 degrees on September 8, 1921.
How often does Orlando hit 100 degrees? The official NWS temperature is taken at Orlando International Airport (MCO). Since 2000, that device has recorded 100 degrees only twice: June 19, 2015, and August 12, 2023.
What are the signs and symptoms of heat stroke, heat exhaustion, heat cramps, and heat rash?
View the graphic below from the CDC and NOAA to see the difference between heat exhaustion and heat stroke, as well as the common signs and symptoms associated with each.
What is heat stroke?
Heat stroke is considered to be a serious heat-related illness and can be deadly if not treated. It happens when the body can no longer control its temperature and is unable to cool down. Common symptoms include confusion and slurred speech, loss of consciousness; hot, dry skin; seizures; and very high body temperatures, sometimes up to 106 degrees or higher.
What is heat exhaustion?
Heat exhaustion is how the body responds to an excessive loss of water and salt, usually due to extreme sweating, according to the CDC. Common symptoms include headache, nausea, dizziness, weakness, irritability, heavy sweating, and decreased urine output.
What are heat camps?
Heat cramps primarily impact workers who sweat a lot during strenuous activities, according to the CDC. Common symptoms are muscle cramps or pain and spasms in the abdomen, arms, or legs.
What is heat rash?
Heat rash is a skin irritation caused by excessive sweating. Symptoms include red clusters of pimples or small blisters on the skin. The rash usually appears on the neck, upper chest, groin, under the breasts, and in elbow creases, per CDC.
The Source: The National Weather Service issued an extreme heat warning until 7 p.m. on Tuesday night, and a heat advisory until 7 p.m. on Wednesday for several counties.