Contrary to popular belief, frost is not what runs the wolves out of the squirrels. They come out of the squirrel after feeding for a few weeks. Usually by the time frost comes the wolves have already done their thing and gone.
Right after a fresh rain they pop out and are real active. This time of year a good patch of hickory trees will always have some cutting. You take a couple quarters with you and grind the edges together....they’ll stick their head right back out. Their nosier than any mother-n-law You ever met.
As soon as the leaves fall. Still plenty of food and you can see them. Squirrels are not as busy late season because most of the acorns are gone and they'll be cutting pine cones. They seem to be out more on over cast days. There are always exceptions and squirrels will be out somewhere. I have even treed two at night. The best time is when you get a chance go.
This time of year before the acorns, in the mountains, just find some hickories with nuts and you'll have squirrel's way up high cutting. Time of day doesn't really matter but early morning/late evening will be cooler.
Same as fishing ,early a.m., late p.m. if on your own.. I go at anytime in woods
with nest. If you have a partner ,one of you smack the tree with a old fence
post and be ready. Also, pull the vines going up the trees especially ones
with nest. Best fun you can have with a young'in.