Hi Mike, A Happy New Year too You.  I live in Rochester, we've had some amazing weather here so far.  But the cold has finally shut down all the courses.  I don't mind playing in the cold, just when it's damp and cold seems to go through you worst than just a sunny cold day. That's where I draw the line.  

Here's to a early Spring

Great question!  One factor to also consider is the wind.  At 45 degrees and a 15 MPH wind, it is much colder than the temps suggest.   I have played in the 40's with a stiff breeze and it is brutal on the hands and there is no feel at that point.  You can keep your hands generally warm, but without the feel of the shot, I find it unplayable...

I'm from the Berkshires in Massachusetts and played right up to just before Christmas,  which was very unusual.  I will not play if the temps. go below freezing. 

You forgot , under 60*. I live in Fl. and I am a wussy.

As long as a course is open I'll play. Some of my most memorable moments on the golf course have come in horrible weather. We still talk about a round last year in North Carolina when all 18 greens were frozen. It made for some interesting golf but we all had a blast and a lot of laughs. 

i played last weekend in probably the coldest temps ever, at around 20 deg. had to purchase some winter gloves, and they actually worked quite well!