Florida does not have four seasons. It has two, which I will refer to as "sprummer" and "falter" which the verbally adept among you will quickly recognize as amalgams of spring/summer and fall/winter.
"Falter" which usually encompasses the months from early November to early/mid February is the shorter of the two seasons--and getting shorter it seems each year. This season is distinguished not so much by the presence of cool (let alone) cold weather, but rather by the absence of the humidity usually so abundant in Florida--and which causes Floridians to look soaked if they stand outside for at least 90 seconds.
Shopping for sprummerware is more of matter of having a discerning touch than eye. One must, upon feeling the fabric of the clothing in question, sense that it is sufficiently porous to allow the passage of air easily while being substantive enough to absorb several hours worth of heavy perspiration. Many t-shirts sold by national clothing chains, for example, are made of a fabric too heavy to be accomodating in subtropical weather. Personally, I find 50% cotten/50% polyester to be a good combination.