Broke records set in 1970 and 2010, respectively

Most every day recently local residents have joked on social media about the heat. One post equated Florida with the surface of the sun. Another, circulated on Monday, said: “Welcome to Hotober.”

Well, it was not your imagination that September seemed hotter than normal. It was the hottest September on record for many towns in central and north Florida, including Gainesville and Ocala, according to the National Weather Service.

The weather service determines the average temperature for a month by averaging the average daily low temperatures with average daily high temperatures. Gainesville broke its record, set in 1970, and Ocala broke the record set in 2010.

Gainesville’s daily average temperature during September was 83.5 degrees. That is 5.3 degrees warmer than the average September temperature, but the weather service didn't say what the old record temperature was.

Ocala’s daily average for September was 82.5 degrees, or 2.6 degrees above the normal average. The weather service didn't say what the old record was.

Gainesville’s daily average high temperature for September was 93.3 degrees. The low temperature averaged 73.8 degrees, the highest average low temperature ever recorded in Gainesville during September. The all-time hottest average daily temperature for Gainesville in September was 93.9 degrees in 1925.

Ocala’s daily average high temperature for September was 92.4 degrees. The low temperature averaged 72.7 degrees. The all-time hottest average daily temperature in September was 93.1 degrees in 1936.

One reason Gainesville and Ocala broke records is that a high-pressure ridge blocked most afternoon thunderstorms from forming. Those storms usually cool the region by a few degrees each afternoon.

Gainesville only received 2.84 inches of rain in September, which is about half of its typical rainfall for the month. Gainesville’s official weather station is at the Gainesville Regional Airport.

Ocala only received 2.91 inches, about half of its 6.08 average dating back more than a century.

Ocala’s official weather station is located at the city’s water treatment plant off Southeast 36th Avenue, just north of Maricamp Road. Temperatures and rainfall totals can vary significantly throughout Marion County, which is larger than Rhode Island.

Scott Cordero, a National Weather Service meteorologist in Jacksonville, said the region did not get its typical afternoon thunderstorms. Typically afternoon sea breezes from the Atlantic Ocean and the Gulf of Mexico collide in the middle of the peninsula along the Interstate 75 corridor.

But this year, that high pressure stifled that activity, and temperatures often reached the mid-90s without that afternoon relief. The end result: hotter than normal temperatures across central Florida.

The weather service’s Climate Prediction Center is predicting a 70 percent chance of an El Niño onset during winter 2018-19. That usually means a warm, wet winter in this part of Florida.

El Niño is a weather phenomenon that occurs when the eastern Pacific Ocean water near the equator becomes warmer than average. That causes changes in weather patterns worldwide.

The stronger the El Niño, the more likely the region could experience weather extremes. El Niño is good in that it helps protect Florida during hurricane season, but it does bring threats.

In this area of the country, El Niño tends to throttle hurricane development by sheering off the tops of building tropical systems, which is happening this year in the Caribbean Sea.

El Niño is also known to allow severe lines of thunderstorms to pass through Florida in the winter.

A strong El Niño also happened in 2007, when what has been dubbed the “Groundhog Day tornado” blasted through Lady Lake, killing eight people, and then slammed Lake Mack in northern Lake County, killing 13 more.

In 1998, another strong El Niño was in place when Florida had one of its worst tornado outbreaks in history. Two killer tornadoes struck in Kissimmee and Daytona Beach, killing 42.

In March 1998, Marion County had record flooding. Then a record drought set in and, by Memorial Day, the state was experiencing one of its worst wildfire outbreaks.

What happens in this part of Florida will depend on how strong this El Niño winter becomes, Cordero said. He added that only time will tell what kind of winter that El Niño will bring Gainesville and Ocala.

Joe Callahan can reached at 867-4113 or at joe.callahan@starbanner.com. Follow him on Twitter @JoeOcalaNews.