For those of you dreaming of a white Christmas, you can find places that have the best chance of being a winter wonderland according to weather history. The “Historical Probability of a White Christmas” map shows the climatological probability of at least 1 inch of snow being on the ground on December 25 in the contiguous United States. On the map, dark gray shows places where the probability is less than 10 percent, while white shows probabilities greater than 90 percent.