I have noticed just recently that there is a white furry hairy fungus covering in patches on both lawns. It seems to be growing on the grass itself. It looks like spider webs but I actually thought when I first saw it a week ago that it was frost that had not thawed. I have since mowed both lawns and am considering whether I should feed the lawn with a weed, feed and moss killer.
Certified GKH Gardening Expert
Dollar spot fungus is a possibility. This disease starts out as fuzzy white growth on lawns, and later can kill grass in spots:
Snow mold looks similar, but it usually appears after snow melts: