We're from the midwest and have learned to EXPECT ANYTHING as the weather goes in off-season Orlando.
We always pack winter and summer-wear.
In Dec/Jan/Feb we have even worn LONG THERMAL UNDERWEAR (after sundown)... we now pack it for any off-season trip.
Typical day:
Cool outside at 7am.
Wear shorts and Tee's.
Over that add a thin nylon wind-breaker
We put our "chilly-wear" and RAIN ponchos in a back-pack.
(Rain ponchos are REALLY cheap in hunting section of discount retailers.
You can buy BIG THICK ones to allow covering large jackets... more later.)
"Chilly-wear" is a nylon cotton-lined warm-up suit with zipper legs and a cotton-lined windbreaker.
We buy OVER-sized in these so they can easily be put on OVER other clothing.
After standing in the sometimes chilly "early-entry" lines we can usually take off the wind-breakers.
We always rent a locker at the park(s) and leave our "chilly-wear" in the locker 'til sun-down.
If it looks like rain (in Florida? Who'da thunk?) we take the Ponchos.
Much later, if its a warm night, we're just fine in the shorts.
If it turns windy/cool... we can visit the locker and choose which level of "chilly" OVER-WEAR to add to our clothing.
If it turns really COLD (windy 30's-40's not unheard-of at certain times of the year) we can make a restroom trip and slide-on the long underwear... OR... we can even add the final outer-layer of the RAIN ponchos (with their HOODS)... OVER everything else.
That trick (along with ear-muffs and gloves) has allowed us to "comfortably" stay and enjoy Fantasmic! or IllumiNations when others (less-prepared) have been "frozen-out."