RE: Are carbon arrows weather proof???
I do not think carbon expands and contracts with temperature change. That is one of the reasons people have switched to carbon from aluminum. However, water does expand and contract and if moisture gets into the fibers in any way it can start to cause cracks in the shaft. Each freeze thaw cycle can increase the size of the cracks. As JeffB states the aluminum insert will do the same. Depending on how many times you shot the arrows I wouldn't recommend shooting them.
Even if you did look at the outside of the shaft and it looks fine the shaft can be damaged from the inside out at the insert.