we got an observation hive a couple of months ago (http://forum.beemaster.com/index.php?topic=8307.0)
and we are getting our bees for it today. Only one prob, rain. Pics are sure to follow.
I wouldn't let a little sprinkle stop you. A downpour, I would try to wait out. Make sure the package has food (either in the can or spray it on the side).
dad had a good idea, he put them in on the porch that has a roof on it. Man do they buzz alot.