Local here, I live in Winter Garden
I'm wearing shorts right now... the high today is somewhere between 88 and 90 - with a chance of rain of course...
Florida weather is so fickled... and can not and will not make up it's mind for anything...
I would say to keep you from over packing and bringing everything, I would add in some tide pods or whatever your brand is, and do a load of laundry... if you need to..... and mix and match what you bring...
Watch the weather the week or so before...
So with that said... I looked back at some pictures from last year... several shots we both had on shorts, DH a T-shirt or polo, and I had on a nice sleeveless shirt and one or two with short sleeves shirts... one picture we both had on jeans it was at Epcot at night, short sleeve shirts underneath and both had on our Disney hoodies, ( there were Christmas decorations in the background so in December for sure most likely Candlelight processional ), one picture we had on shorts and shirts, and I had on a jacket, DH did not have a jacket on.
Shorts
T-shirts, I like nicer shirts so I stick with that...
Hoodie or a lightweight jacket that can double - jacket and rain jacket if needed.. with a zipper... it gets hot standing in the line, and now that the lines snake out so much and not much shade in some spots, it will be easier to take off and put back on again.
Couple pairs of jeans
Leggings or exercise wear
For the kids, I would plan on bring both for each day... as you can throw a pair of jeans in the day bag and be good to go. Hoodie or Jacket and mittens, and a watch cap.
Depending on your kids, maybe a blanket( lightweight) for in the stroller... with the hours in the parks ever changing, this is one of those things that can go either way... Or you could just buy one if you feel the need... everyone can always use a Disney blanket... as well I know that this might not pertain to your kids... but sometimes a blanket from home with a familiar smell helps the kids sleep easier...
Tennis shoes, deck shoes or loafers and socks... especially for the kiddo's
By the way, you might want to bring a swim suit, guest will be swimming still for sure... the pool are heated...