All you need to know is basically this...
Trees are made of wood. Wood is very porous, meaning it can hold water easily.
What season you are going to be cutting and working a felled tree in will affect the quality of the wood a lot actually. Personally i like cutting in the winter because the wood is the driest, so it is more brittle and easier to cut.
What to think about is not just the amount of water on the ground or from recent rain/snow, but from how much is in the air. Summer months typically bring humid weather and the wood quality in a tree will reflect this, making it it more spongy. So if you are chipping it with an adze or an axe the tool will tend to bounce more and make less precise and effective cuts. Fall and spring may have similarly dry humidity levels, but spring wood will be a little more spongey than fall because heavy snow melts will bring increased saturation to the trees. Dry wood is much more brittle and susceptible to split and chip. Which is actually a plus if you are stripping bark, or milling it somehow. It's all about water density in the air. Hope that helps.
