Calling this winter "relatively short" ...don't know about that, Dec and Jan both with -3.5° temp departures and double normal snowfall for many of us. Feb with a -9° departure so far. Of course we've been so dry this month however.
Unfortunately I don't have records for various time ranges...if you use calendar months then a 20° mean would put it near my coldest on station record ... Of course that would be for 30 days .
January here finished as the coldest month since Feb 2015 with a 28.3° mean, even with an 8 day thaw from the 8th thru the 15th where the temp hit 50° five times. Snowfall of 17.6" and precip of 2.79".