Mr. Greenjeans, I fret plenty over my spoiled girls here in the South, and we found an interesting way to keep air moving - - but not too much - - in the coop. (Too much direct wind is bad for chicken respiratory systems.)
We pulled the fan out of the back of an old computer and mounted it over a hole we already had in a protected wall of the coop about 6" from the ceiling. (Of course, you have to have electricity hooked up to do this.) The fan runs on DC current, so we had to plug it into an AC-to-DC transformer to hook it to the coop power cord. You can get a transformer at Radio Shack or Wal Mart in the states. Make sure you match the output voltage of the transformer to the fan ~ in our case, 12V. Some transformers are universal (adjustable).
The computer fan is small, uses little energy, and makes very little noise. We positioned it so it sucks hot ceiling air OUT of the coop, instead of blowing it in. I also keep a remote thermometer about 8" from the coop floor, and this fan has reduced the coop temp by a few degrees. You can feel the difference just sticking your hand in the doorway.
The adjacent wall of the coop also has a regular white household vent about 8" from the ceiling, and the holes are tilted so water does not sneak in. I also sealed around it with clear silicone. On the inside of the vent hold I can place a small piece of cardboard in the winter to control the amount of air flow.
It is so incredibly humid on our Tennessee summer nights that my girls even have a super-reinforced summer screened door for their coop. It's double-layered with screen and 1/2" hardware cloth, so the air flows through but 'coons don't!
That said, our coop sits under the polycarbonate roof of a covered run, so it is protected from rain and snow. You would definitely want weather protection so water doesn't get into the coop or into the electronics.
Hope that helps! Good luck.
Jenski in Middle Tennessee