Cooler air masses are on the way, but they will be far from what we consider cold around these parts. Temperatures will bottom out in the lower 50's both Wednesday and Thursday. And high temperatures will reach the 70's.
Major Frontal Boundary For Midweek
With the cooler on the way, it is good to look at past cold snaps. Jacksonville's earliest freeze, in recorded history, was on November 3, 1954. North Florida and South Georgia usually average the first freeze on or around December 6th.
(For curiosity's sake) Jacksonville's earliest snowfall was recorded on November 28, 1911. (Just a trace of measurable snowfall fell)