Happy smoking and don't worry about the weather, 2 of my 5 smokes have been done in the rain, one in showers, the other continual rain from start to finish.
Get your hands on some good quality charcoal and a few racks of baby back ribs, sit back and enjoy.
Oh and don't forget the first burn to get rid of any factory nasties that may be lingering. As someone told me, if it was absolutely necessary there would be a big red sticker on it telling you to first burn but it does give you a, no risk, chance to mess about with temperature regulation.