National Weather Service United States Department of Commerce
Autumn Has Begun, So When Does It Usually Cool Off
Across West Central And Southwest Florida?

Astronomically speaking autumn began at 9:54 PM EDT Saturday September 22, but across West Central and Southwest Florida the temperatures will remain anything but fall-like. We will continue to have rather high humidity with dew points in the middle 60s to middle 70s, along with high temperatures in the mid 80s to lower 90s.

During most years we do not see the first shot of cooler drier air until the middle of October, albeit usually is rather short lived lasting only a day or two, with the real cool down not occurring until November. A good way to examine the timing of the first cool down is by looking at overnight low temperatures. The overnight low temperatures are highly dependent on a few factors, not the least being the amount of moisture in the air near the ground measured by looking at the dew point, the amount of cloud cover, and winds. In general overnight low temperatures cannot fall below the dew point, therefore if the dew points are still in the middle 60s to middle 70s as they are now, then the overnight low temperatures will most likely also be in the mid 60s to mid 70s unless a cool front moves through during the night. So to see when the first cool front moves across the region we’ll take a look at the dates when low temperatures fall below different thresholds at some locations.

Examining the tables below we do see that the average time of the first real cool front appears to be during mid-October. This is when temperatures generally fall into the mid 50s across inland portions of the Nature Coast and below 60 degrees elsewhere across West Central and Southwest Florida. The only exception is near the coast where the water keeps temperatures higher and these areas take longer to fall below 60 degrees, as seen at St. Petersburg.
 

Date of First Low Temperature ≤ 60°F   Date of First Low Temperature ≤ 55°F
          Records                   Records
Site Earliest Latest Average 2017 Began   Site Earliest Latest Average 2017 Began
Arcadia Sep 16 1962 Nov 19 1911 Oct 11 Oct 25 1901   Arcadia Oct 1 1920 Dec 4 1986 Oct 24 Oct 26 1901
Archbold Sep 8 1997 Nov 4 2007 Oct 6 Oct 26 1969   Archbold Sep 29 2006 Dec 3 1986 Oct 20 Oct 26 1969
Bartow Sep 16 1913 Nov 14 1946 Oct 14 Oct 25 1892   Bartow Sep 24 1916 Nov 25 1922 Oct 23 Oct 26 1892
Brooksville Sep 16 2001* Nov 4 1900 Oct 8 Oct 24 1892   Brooksville Sep 19 1981 Nov 14 1946 Oct 19 Oct 24 1892
Bushnell Sep 9 1997 Nov 3 1969 Oct 6 Oct 25 1948   Bushnell Sep 27 1956 Nov 14 2015 Oct 15 Oct 25 1948
Chiefland 5 ESE Aug 27 1969 Oct 25 1959 Sep 27 Oct 18 1956   Chiefland 5 ESE Sep 10 1963 Oct 27 1994 Oct 7 Oct 22 1956
Fort Myers Oct 1 1920* Dec 3 1986 Oct 26 Oct 25 1902   Fort Myers Oct 1 1920 Dec 11 1994 Nov 4 Oct 30 1902
Inverness 3 SE Sep 09 1997 Oct 25 2017* Oct 7 Oct 25 1948   Inverness 3 SE Sep 16 1956 Nov 4 1985* Oct 15 Oct 25 1948
Lakeland Sep 19 1981 Nov 14 2015* Oct 17 Oct 25 1915   Lakeland Oct 1 1920 Nov 25 1948* Oct 26 Oct 26 1915
Mountain Lake Sep 19 1981 Nov 4 2007* Oct 11 Oct 25 1935   Mountain Lake Sep 21 1938 Nov 22 2015 Oct 21 Oct 30 1935
Myakka Rvr St Pk Sep 19 1981 Nov 14 2015 Oct 10 Oct 25 1956   Myakka Rvr St Pk Oct 2 1984 Nov 23 2015 Oct 23 Oct 26 1956
Plant City Sep 15 1918 Nov 14 2015 Oct 11 Oct 25 1893   Plant City Sep 20 1981 Nov 23 2015 Oct 20 Oct 26 1893
Punta Gorda Oct 2 2001* Nov 23 2015 Oct 21 Oct 25 1914   Punta Gorda Oct 9 2000 Dec 5 1946 Nov 1 Oct 25 1914
Sarasota-Bradenton Sep 20 1981 Nov 23 2015 Oct 15 Oct 26 1911   Sarasota-Bradenton Oct 1 1920 Nov 25 1922 Oct 27 Oct 29 1911
St. Leo Sep 18 1910 Nov 8 1919 Oct 11 Oct 25 1895   St. Leo Sep 19 1981 Nov 15 1919 Oct 20 Oct 26 1895
St. Petersburg Oct 2 1920 Dec 4 1986 Oct 28 Oct 30 1914   St. Petersburg Oct 1 1920 Dec 15 1998* Nov 8 Oct 30 1914
Tampa Sep 19 1981 Nov 15 1919 Oct 17 Oct 25 1890   Tampa Sep 22 1897 Nov 25 1948* Oct 27 Oct 29 1890
Tarpon Springs Sep 19 1981* Nov 15 1919 Oct 12 Oct 26 1892   Tarpon Springs Sep 20 1981 Nov 25 1922 Oct 22 Oct 27 1892
Venice Sep 27 1956 Nov 23 2015 Oct 19 Oct 25 1956   Venice Oct 3 1974 Dec 3 1986 Oct 29 Oct 26 1956
Wauchula 2 N Sep 19 1981 Nov 23 2015 Oct 14 Oct 25 1933   Wauchula 2 N Sep 27 1956 Nov 23 2015 Oct 24 Oct 26 1933
Winter Haven Sep 19 1981 Nov 14 2015* Oct 18 Oct 29 1941   Winter Haven Oct 4 1974 Dec 3 1986 Oct 27 Oct 29 1941
                               
Click on a "Site" name for graphs at each location
 
                               
Date of First Low Temperature ≤ 50°F     Date of Earliest Freeze (≤ 32°F)    
          Records               Records    
Site Earliest Latest Average 2017 Began     Site Temp Date Began    
Arcadia Oct 1 1920 Dec 11 1994 Nov 1 Oct 26 1901     Arcadia 32° Nov 11 1956 1901    
Archbold Oct 8 2010 Dec 19 2015 Oct 30 Oct 26 1969     Archbold 29° Nov 15 1975 1969    
Bartow Oct 1 1920 Dec 16 1998 Nov 1 Oct 26 1892     Bartow 30° Nov 12 1913 1892    
Brooksville Sep 22 1897 Dec 4 1905 Oct 28 Oct 25 1892     Brooksville 29° Oct 29 2008* 1892    
Bushnell Oct 2 2011* Nov 14 2015* Oct 23 Oct 26 1948     Bushnell 30° Nov 1 1954 1948    
Chiefland 5 ESE Sep 20 1981 Nov 14 2015 Oct 14 Oct 22 1956     Chiefland 5 ESE 32° Oct 21 1989 1956    
Fort Myers Oct 18 1977 Jan 16 1972 Nov 18 Dec 10 1902     Fort Myers 32° Dec 10 1917 1902    
Inverness 3 SE Sep 27 1991 Nov 23 2015 Oct 23 Oct 26 1948     Inverness 3 SE 31° Oct 28 2008 1948    
Lakeland Oct 1 1920 Dec 15 1919 Nov 5 Oct 30 1915     Lakeland 31° Nov 24 1970 1915    
Mountain Lake Oct 8 1987 Dec 5 1946 Oct 30 Oct 30 1935     Mountain Lake 26° Nov 16 1940 1935    
Myakka Rvr St Pk Oct 8 1987 Dec 4 1986 Nov 1 Oct 26 1956     Myakka Rvr St Pk 32° Nov 24 1956 1956    
Plant City Oct 4 1929 Nov 25 1948 Oct 29 Oct 26 1893     Plant City 32° Nov 4 1966 1893    
Punta Gorda Oct 14 1977 Jan 2 1987 Nov 11 Oct 30 1914     Punta Gorda 28° Nov 25 1970 1914    
Sarasota-Bradenton Oct 2 1920 Dec 19 2015 Nov 5 Oct 30 1911     Sarasota-Bradenton 27° Nov 17 1940 1911    
St. Leo Sep 22 1897 Nov 30 1958 Oct 31 Oct 30 1895     St. Leo 31° Nov 15 1969 1895    
St. Petersburg Oct 17 1943 Jan 7 2017 Nov 21 Dec 10 1914     St. Petersburg 32° Dec 7 1937 1914    
Tampa Oct 11 1906 Dec 15 1998* Nov 7 Oct 30 1890     Tampa 31° Nov 16 1940 1890    
Tarpon Springs Oct 1 1920 Dec 5 1919 Nov 2 Oct 30 1892     Tarpon Springs 31° Nov 16 1940 1892    
Venice Oct 14 1977 Dec 19 2015 Nov 10 Oct 30 1956     Venice 29° Nov 25 1970 1956    
Wauchula 2 N Oct 10 2000 Dec 4 1986 Nov 1 Oct 26 1933     Wauchula 2 N 29° Nov 11 1956 1933    
Winter Haven Oct 10 2000 Dec 12 1994 Nov 4 Oct 30 1941     Winter Haven 31° Nov 24 1970 1941    
                               
*Last of Multiple Occurrences                            
                               

Click on a "Site" name above for graphs at each location
 
 

 

Another way to look at when it may cool down is to take a look at the graphs of the average (based on 1981-2010 Normals) and record low temperatures during the autumn at a few sites across the region. We can see from the graphs below that during some years the first cool down has occurred as early as mid-September when temperatures have fallen into the upper 40s across northern portions of the Nature Coast to the lower 60s south. However, looking at the average lows we see that for the most part it takes until November before low temperatures fall into the mid 50s north to lower 60s south on a consistent basis. Also on these graphs we can see that on a few rare occasions there has been a freeze across portions of the Nature Coast during the second half of October, with areas further south during November.

 


Chiefland 5 ESE data
 
(Back to Tables)
 


Inverness 3 SE data
 
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Bushnell 1 E data
 
(Back to Tables)
 


Brooksville Area data
 
(Back to Tables)
 


St Leo data
 
(Back to Tables)
 


Tarpon Springs data
 
(Back to Tables)
 


Tampa Area data
 
(Back to Tables)
 


St Petersburg Area data
 
(Back to Tables)
 


Plant City data
 
(Back to Tables)
 


Lakeland Area data
 
(Back to Tables)
 


Winter Haven Area data
 
(Back to Tables)
 


Bartow Area data
 
(Back to Tables)
 


Mountain Lake data
 
(Back to Tables)
 


Sarasota-Bradenton Area data
 
(Back to Tables)
 


Myakka River State Park data
 
(Back to Tables)
 


Venice data
 
(Back to Tables)
 


Wauchula 2 N data
 
(Back to Tables)
 


Arcadia data
 
(Back to Tables)
 


Archbold Bio Stn data
 
(Back to Tables)
 


Punta Gorda Area data
 
(Back to Tables)
 


Fort Myers Area data
 
(Back to Tables)
 
 


As a side note, for those who miss or would like to see where the foliage has begun to change color across the United States, visit the USDA Forest Service web site listed below.

        https://www.fs.fed.us/fallcolors/2018/

And for an idea of the approximate time of peak fall foliage see the image below:

Peak Fall Color Map


For more local climate information, visit our web site at

        https://www.weather.gov/tampabay

and go to the Climate and Past Weather drop down menu above the weather forecast graphics.