It was often in the high 60's with a low of 40's (sometimes dipping down to 38 degrees!) when we were at Disney last week. Please pack a winter coat if you can, or be prepared to buy fleece blankets to wrap members of your family.
From the adults I saw, and in my experience, those fleece blankets sold everywhere are not large enough to cover more than one person.
We are from Chicago, and we used our wool winter coats every night that we were there. (We originally thought we would only use the coats when we returned home from the airport!) We left the coats in the car until mid-day when we would return to the car to pull them out before we hopped to another park. Even with the coats, we were still cold a few nights. The other park guests were FREEZING, even in jeans, and many of them cut their evenings short because they weren't properly dressed for the chilly weather and fierce winds... Everest and Test Track are both partly outdoors and the wind was sharp against our faces when we rode them; I can only imagine how it felt to the other guests. Let's just say that a lot of guests caught colds.
The benefit was shorter or no lines at the parks at night. We were so grateful that we booked our ADRs at indoor restaurants, which guaranteed us some rest in heated buildings in the evenings.
Please pack some pants, at least one long-sleeve shirt, mittens (and hats if you can), and a coat will be a must at night.
