sqwerls are gonna eat on a regular basis. If it is real windy, they will hole up for a while, but not for days. The best days are usually when a front as past, nice frosty morning, and bright sun. But only for the first few hours. When that sun gets to warming up the treetops, they will lay out on the limbs to sun, and you will never see them.
I've actually seen the wind blow their tails around a tree giving him away. I still like calm days though. But for me, I'll try to get in woods ANY day I can!