That certainly could be. Wind & cold weather can make maintaining temps tough. A nice corner on the patio or a windbreak of some sort is helpful. Sometimes an old sleeping bag or quilt wrapped around the unit insulates it enough for a good smoke. Many on this forum just smoke in their garages when the weather is pooey (presumably well-vented in some way). I generally don't have these problems here in CA.
I forgot to mention last night:
NEVER stuff a bird you are going to smoke; bacterial growth conditions are just too good (& bad for you) in that scenario. I also do not close up the ends with skewers either (for the same reason); I want the warm air to circulate all around & through for a good cook & good smokey flavor.
SmokinAl is right: watch our for lingering in the danger zone too long. I've never had a bird take over 5.5 hours at a steady cook temp of 250* in the smoker, so my birds are never in the danger zone very long -- even the big ones. (And, yes, my thermometers are tested and accurate!!)
Good luck, and show us the money!!!!