(George Jiang)

MIAMI — There tend to be two seasons in South Florida: hot and wet from May to October, then warm and dry from November to April. But the past two Decembers have made the tourist-enticing phrase “endless summer” a reality — great for our visitors, not so great for us.

Floridians — especially in the southern half of the state — look forward to ideal winter weather after enduring relentless mega-muggy conditions for six months. Winters are still warm, but things dry out and the oppressive heat takes a leave of absence.

However, much to our dismay, the region is experiencing one of its warmest Decembers on record.


Average temperature rankings across Florida so far this month. A 1 indicates the warmest on record, 2 is second warmest, etc. (Southeast Regional Climate Center)

In 2015 and again in 2016, Miami’s weather in December was essentially no different from that in June or July — high temperatures in the upper 80s, dew points in the upper 70s. The resulting heat index was then in the 90s.

In Miami, over a dozen records have already been broken this month. All of them have been heat-related records; there hasn’t been a single cold record in winter’s first month.

To track record warmth, there are actually three daily values that are worth monitoring: the high temperature, the low temperature and the average temperature.


A timeline of heat-related records during December for Miami. The year when each daily record was set is shown above each marker, with 2016 highlighted in red. (B. McNoldy)

Of the 93 possible records shown in this chart, 33 of them (35 percent) were set just in 2015 and 2016, and 54 of them (58 percent) were set in the past 10 years.

That’s worth repeating: 35 percent of all of our December heat-related records have been set in the past two years, and 58 percent have happened since 2006. That is a stunning statistic, but it shouldn’t come as a surprise in a warming world. Across the country, heat records have far outpaced cold records. By the end of the century, scientists expect that, on average, 15 heat records will be set for every one cold record.

Unfortunately for Floridians yearning for more seasonable weather, the outlook is not promising. The record warmest average temperature and warmest low temperature for the entire month of December were just broken this past Sunday, and it doesn’t look like this pattern will budge. NOAA’s Climate Prediction Center says Florida has a very high likelihood of staying warmer than normal through the end of the month.

In fact, all of the center’s outlooks indicate that south Florida can expect above-average temperatures for quite some time — possibly even through March — breaking more records along the way.


Probability of temperature anomalies over the coming six to 10 days (top), 1 month (middle), and three months (bottom). (NOAA/CPC)