It’s always surprising to find any form of life crawling on top of the snow, but for some reason spiders seem particularly fragile and susceptible to the elements. There are species, however, that remain active in winter, even in the northeast. Most live in the leaf litter beneath the snow, but they often emerge when temperatures are about 25°F to 35°F. Tentative I.D. has the spider in the photograph belonging to the genus Tetragnatha.