Some Wet Season Statistics from North Melbourne, Florida
 
It is commonly stated that east central Florida gets most of its rainfall during the Wet Season. But how much is “most?”  Examination of 22 years of data at a north Melbourne rainfall station revealed that nearly two thirds of the yearly rainfall occurred during the Wet Season. The Wet Season length was 138 days, or about four and a half months. Stated more specifically, 64 percent of the rainfall occurred in 38 percent of the year.
 
How much rainfall do tropical cyclones contribute to the Wet Season and yearly totals? For the 1992-2013 period, tropical systems provided 15 percent of the Wet Season rainfall and 10 percent of the yearly total, on average. That amounts to about 5 inches per year. Of course some years have much more, but in many years tropical systems provide little/no rainfall. 
 
One last piece of data that is worth delving a little deeper into is categorical rainfall totals. Typically, the number of days with 0.01 inches or more (measurable rainfall) is quoted in climatological data.  Melbourne receives measurable rainfall on 100-105 days in an average year. However, some of our drier years actually had measurable rainfall on more than 105 days. 
 
The number of days with heavy downpours of one inch or greater provided a better perspective. For the 1992-2013 period, there were an average of 10 days per year with rainfall from 1-2 inches and 4 days with totals exceeding 2 inches. That is 14 days with 1 inch or greater rainfall. In the very dry years of 1993 and 2013, these “heavy downpour” days were fewer (only 8 days with 1 inch or greater rainfall). 
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Randy Lascody
May 2014

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