On Tuesday this week the low was minus 28 degrees Fahrenheit and the high 15 degrees. Temperatures for the previous seven days were below zero at night and zero or just slightly above during the day. Today, the air temperature is 28 degrees and when I went out to check for eggs this morning I saw this spider walking across the path. It is a member of the wolf spiders (Lycosidae) although I am not sure which species. It seems closest to the genus Pirata. Young and mature adults overwinter (hibernate) and it is actually very common for them to come out on warm days. Several other spider species also venture out on warm winter days.
Spiders of the Northwoods by Larry Weber (2003). Kollath-Stensaas Publishing. Duluth, MN