PatsGirl said:
Can I use these websites with any accuracy?
As much as you can trust any long-term forecast in a part of the country that gets all kinds of weather.
(Which is not TOO much trust.)
When we go to WDW in the cooler months, we pack shorts and Tees... all the way up to long-underwear, gym warm-ups and heavy jackets (many times worn in combination). Don't forget hats and/or earmuffs (we get plenty of folks on a cold day asking where they can buy earmuffs).
We start out with jackets in the AM (put in lockers when it warms up) and then add layers until "toasty" for even a chilly IllumiNations, Wishes, etc.
You just never can tell about weather.
I always LOOK at weather.com, but I don't EVER trust ANY form of weather-casting.
And, I will not let an "unexpected" spate of weather to ruin our fun.
Maybe you could buy another soft-sider suitcase to pack the extras... it COULD save your trip.