About the only requirement for them to get out and about
is: Sunshine.
Even in the dead of winter, days the sun comes out. they'll be out running around on the snow even. Not everday, but, a majority of the time they will be.
A light drizzle won't put them all down, even a light rain sometimes won't.
One thing about this area, when it rains, it's RAINING. Soon as it stops, it's done and gone, an the sun will be out shortly. When it is, get back to shootin as they'll be out.
George