Seasons effect on dreams?

I find that in the summer dreaming is almost effortless. I put a bit of effort into remembering my dreams clearly, but in the summer I do this without effort and only need a little more concentration to become lucid. Come fall and early winter it gets harder to remember dreams at all and I need to shake myself up and use a lot of tricks to have to same results.

I suppose it started that way because of the shift from school to summer vacation for two months and kept that habit after graduating even though my schedule doesn't change that much any more.

Does anyone else find it easier to become lucid in the summer?