A lot of if depends on whether you want to shoot white or brown hare, and if you want to run on snow or not.
It's hard to beat October, it's usually cool and damp and the dogs can pound. Also the hare numbers are at the highest they will be for the hunting season. November is good but it's deer season in Maine, you'll have to watch where you turn the dogs loose.
I've gone in December before and the first day we hunted it was 24 below zero, it's hard for me to get guys to go back up there that time of year now.
Give Bob or andrea a call at http://pinegrovelodge.com/ . I hunted hare back in 2000 there and oct. is a great time to go.You can rent their cabins and public land is about 5 min. away...it's close to Bingham.. ...about 10 -11 hr. drive from central PA
I generally make 3-5 trips a year to the north woods.
Usually go in mid October, Thanksgiving week, Jan. or Feb depending on conditions (I have a Buddy up there that calls) and then we close the season out mid to late March in NH.
Like John said the early hunt is fun, great running, makes you think your dogs are immortal LOL. but the hare are still brown and the woods can be thick if the Frost hasn't done it's job.
I would say mid November would be a winner. The critters are mostly white, running is still great. Only thing is the deer hunters but they haven't bothered us much.
we did have 1 stop at the cabin one night and ask us not to run a particular spot. So we didn't but mostly we see road hunters up there.
Love the spring too, The hare are concentrated and it can get fast and furious. But you do get the occasional March hare that takes off for a mile or two.
Best I can say is get up there when you can, It is a beaglers heaven.
I've been going the end of March for many years. It's the classic hare hunt...lots of snow...hunting on snowshoes and lots of hares. We kill as many or more hares then as the guys who go early so don't worry about that.