White Christmas odds are low to begin with in cities like New York (13%) and Chicago (34%), so how could El Niño change snow chances this December? Looking back to 1950, average Christmas Day snow depth swings from 6.3 inches in Denver during super El Niños to 0.2 inches in Chicago and none in New York or Washington, D.C. Our December outlook looks better for snow in the Southwest and southern Rockies than in the Northeast and western Great Lakes, but this is historical odds, not a forecast, so check back in mid-December.