The decade ended with another history-making temperature benchmark with 2019 tying for the third-warmest year in West Palm Beach in records dating back more than a century.
The overall average temperature of 77.5 degrees was 2.1 degrees warmer than normal, the same as 1990, but behind 2015 and 2011, which rank as the hottest and its runner up, respectively.
Much of the abnormal heat this past year was felt in the overnight hours. While the daytime peak temperature at Palm Beach International Airport averaged 84.5 degrees — 1.6 degrees above normal — the overnight average of 70.5 was 2.7 degrees higher.
That lack of nighttime cooling concerns Ben Kirtman, a professor with the University of Miami’s Rosenstiel School of Atmospheric Science and director of UM’s Cooperative Institute for Marine and Atmospheric Studies.
“A lot of communities in Florida rely on nighttime temps cooling down so they can open their windows and give the air conditioning a break,” he said. “Basically, the discussion in South Florida has been dominated by sea level rise, but we are going to be talking about heat much more as we go forward.”
A trend toward warmer temperatures in 2019 was seen statewide, according to the Southeast Regional Climate Center. The year may rank as Florida’s hottest or second hottest when the National Oceanic and Atmospheric Administration releases its final statewide results Jan. 8.
Through November 2019 was the warmest on record for Florida with an average temperature of 74.1 degrees. That’s 2.9 degrees warmer than the norm calculated from 1901 to 2000. In second and third place statewide were the years 2017 and 2015, respectively.
Palm Beach County was similarly warm January through November with an average temperature of 77.2 degrees — a whopping 3.1 degrees above normal. That’s enough to rank it second for warmest year on record behind 2017.
Sean Sublette, a meteorologist with Climate Central, said it’s telling that the top five warmest years on record have been primarily since 2011. In West Palm Beach, 1990 and 1911 are outliers, but 1911′s data is suspect with 75 days of temperature readings missing.
“We do want to remind people that it’s not exclusively climate change, but it plays a large role,” Sublette said. “There will always be variations from year to year but as we continue to move forward, these instances where it’s very warm will continue to outnumber the times when it’s cooler.”
There is some debate about whether 2019 in Miami tied 2015 for hottest year or came in second place. According to the National Weather Service in Miami it depends on how the annual temperature is calculated.
If an average of all the days of the year is measured, the temperature for 2015 is 79.2 degrees, which is 0.1 degrees warmer than 2019, said Robert Molleda, warning coordination meteorologist for the NWS office in Miami.
“However, if you go by the average of months, which is the National Weather Service convention, then 2015 was 79.1 degrees, which would be equaled by 2019 and thus making it tied for the warmest year on record,” Molleda said. “Normally, 0.1 degrees is inconsequential, but in a case where it makes a difference between a record-setting value and a near-miss, it matters, at least from a technical standpoint.”
NOAA says, on average, Florida has warmed by approximately 1.2 degrees since 1895, and appears to be warming at a rate approximately four times faster in the last 40 years than over the last 100 years or so.
This past year, much of the country had near normal to below normal temperatures with the southeast sticking out like a stubbed toe with abnormal heat.
“That’s part of the variability,” Sublette said. “Also, we know the arctic is warming twice as fast as the rest of the world, so the source of the cold air will not be as cold consistently.”