Last year I took a kid out for the Iowa youth season in north Iowa. That morning it was 28 degrees and it was VERY clear and the birds were going INSANE! They would start at one end of a 2 mile long stretch of woods and go all the way down and then all the way back. it was like the wave. One of the coolest things Ive ever heard. Also ended up getting one of those gobblers to come in strutting and everything. I'd say if it looks like its gonna be a good clear day to dress warm and hit em hard, but they may not want to gobble. Sometimes its hard to tell. just my two cents