If you are concerned about it being too hot for batting, we had the worst winter last year in history. Many consecutive days with temps not going over 50 degrees. Are you going to hand quilt it? If so, don't use flannel it will kill your fingers. Otherwise if you are machine quilting it, and you like the flatter look, flannel will do fine, I've used it myself for baby quilts (I am a Floridian) but Warm and Natural is fine, too.

What Rita said!

Hi Fran
I make quilts for my grandbabies in Okinawa...the Hawaii of Japan. I just hand quilt my tops to a backing of fleece...2 layers. It works quite well. You just have to be careful what colors you choose so the fleece doesn't show a pattern thru the top. I've never tried to machine quilt fleece.
Bon
:)

I use cotton batting for my Central Fl family and they are able to use it about 3 months of the year.
They like raggedy edge for the other months.
Quilts are also good for lounging on the floor!