Average Weather in December in Fort Myers Florida, United States
In Fort Myers, the month of December is characterized by gradually falling daily high temperatures, with daily highs decreasing by 4°F, from 78°F to 75°F over the course of the month, and rarely exceeding 84°F or dropping below 64°F.
Daily low temperatures decrease by 4°F, from 60°F to 56°F, rarely falling below 43°F or exceeding 69°F.
For reference, on August 7, the hottest day of the year, temperatures in Fort Myers typically range from 75°F to 91°F, while on January 18, the coldest day of the year, they range from 55°F to 74°F.
Average High and Low Temperature in December
The figure below shows you a compact characterization of the hourly average temperatures for the quarter of the year centered on December. The horizontal axis is the day, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.
Average Hourly Temperature in December
The month of December in Fort Myers experiences essentially constant cloud cover, with the percentage of time that the sky is overcast or mostly cloudy remaining about 37% throughout the month.
The clearest day of the month is December 2, with clear, mostly clear, or partly cloudy conditions 64% of the time.
For reference, on July 7, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 69%, while on February 21, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 68%.
Cloud Cover in December
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Fort Myers, the chance of a wet day over the course of December is essentially constant, remaining around 14% throughout.
For reference, the year's highest daily chance of a wet day is 73% on August 11, and its lowest chance is 13% on December 17.
Probability of Precipitation in December
To show variation within the month and not just the monthly total, we show the rainfall accumulated over a sliding 31-day period centered around each day.
The average sliding 31-day rainfall during December in Fort Myers is essentially constant, remaining about 1.4 inches throughout, and rarely exceeding 3.4 inches or falling below 0.1 inches.
The lowest average 31-day accumulation is 1.3 inches on December 17.
Average Monthly Rainfall in December
Over the course of December in Fort Myers, the length of the day is essentially constant. The shortest day of the month is December 21, with 10 hours, 28 minutes of daylight and the longest day is December 1, with 10 hours, 35 minutes of daylight.
Hours of Daylight and Twilight in December
The earliest sunrise of the month in Fort Myers is 6:58 AM on December 1 and the latest sunrise is 17 minutes later at 7:15 AM on December 31.
The earliest sunset is 5:34 PM on December 1 and the latest sunset is 11 minutes later at 5:45 PM on December 31.
Daylight saving time is observed in Fort Myers during 2017, but it neither starts nor ends during December, so the entire month is in standard time.
For reference, on June 21, the longest day of the year, the Sun rises at 6:34 AM and sets 13 hours, 49 minutes later, at 8:23 PM, while on December 21, the shortest day of the year, it rises at 7:11 AM and sets 10 hours, 28 minutes later, at 5:39 PM.
Sunrise & Sunset with Twilight and Daylight Saving Time in December
We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.
The chance that a given day will be muggy in Fort Myers is rapidly decreasing during December, falling from 33% to 22% over the course of the month.
For reference, on July 30, the muggiest day of the year, there are muggy conditions 100% of the time, while on January 30, the leasy muggy day of the year, there are muggy conditions 16% of the time.
Humidity Comfort Levels in December
This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.
The average hourly wind speed in Fort Myers is essentially constant during December, remaining around 4.9 miles per hour throughout.
For reference, on March 13, the windiest day of the year, the daily average wind speed is 5.2 miles per hour, while on August 4, the calmest day of the year, the daily average wind speed is 3.0 miles per hour.
The lowest daily average wind speed during December is 4.8 miles per hour on December 21.
Average Wind Speed in December
Wind Direction in December
Fort Myers is located near a large body of water (e.g., ocean, sea, or large lake). This section reports on the wide-area average surface temperature of that water.
The average surface water temperature in Fort Myers is gradually decreasing during December, falling by 4°F, from 73°F to 70°F, over the course of the month.
Average Water Temperature in December
This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation.
The average daily incident shortwave solar energy in Fort Myers is essentially constant during December, remaining within 0.1 kWh of 3.8 kWh throughout.
The lowest average daily incident shortwave solar energy during December is 3.7 kWh on December 22.
Average Daily Incident Shortwave Solar Energy in December
For the purposes of this report, the geographical coordinates of Fort Myers are 26.622 deg latitude, -81.841 deg longitude, and 13 ft elevation.
The topography within 2 miles of Fort Myers is essentially flat, with a maximum elevation change of 13 feet and an average elevation above sea level of 14 feet. Within 10 miles is also essentially flat (26 feet). Within 50 miles is essentially flat (207 feet).
The area within 2 miles of Fort Myers is covered by artificial surfaces (98%), within 10 miles by artificial surfaces (73%) and herbaceous vegetation (14%), and within 50 miles by water (33%) and herbaceous vegetation (24%).
This report illustrates the typical weather in Fort Myers year round, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.
Temperature and Dew Point
There are 3 weather stations near enough to contribute to our estimation of the temperature and dew point in Fort Myers.
For each station, the records are corrected for the elevation difference between that station and Fort Myers according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations.
The estimated value at Fort Myers is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Fort Myers and a given station.
The stations contributing to this reconstruction are: Page Field (95%, 4.6 kilometers, southwest), Punta Gorda Airport (4.3%, 36 kilometers, northwest), and Okeechobee County Airport (0.7%, 122 kilometers, northeast).
All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Tables of the Sun, Moon and Planets , by Jean Meeus.
All other weather data, including cloud cover, precipitation, wind speed and direction, and solar flux, come from NASA's MERRA-2 Modern-Era Retrospective Analysis . This reanalysis combines a variety of wide-area measurements in a state-of-the-art global meteorological model to reconstruct the hourly history of weather throughout the world on a 50-kilometer grid.
Land Use data comes from the Global Land Cover SHARE database , published by the Food and Agriculture Organization of the United Nations.
Elevation data comes from the Shuttle Radar Topography Mission (SRTM) , published by NASA's Jet Propulsion Laboratory.
Names, locations, and time zones of places and some airports come from the GeoNames Geographical Database .
Time zones for aiports and weather stations are provided by AskGeo.com .
Maps are © Esri, with data from National Geographic, Esri, DeLorme, NAVTEQ, UNEP-WCMC, USGS, NASA, ESA, METI, NRCAN, GEBCO, NOAA, and iPC.