SandyC: Yea, Im sure. My wife and I have been going to GC in December for 10 years. Obviously temps vary year to year (and I dont go out of my way to see what temp it really is) but mid 70's with a stiff breeze is a pretty good guess at night. Will you need a sweater? Who knows, but we like one, especially if we are laying out in a hammock at night.