In reply to girlymonkey:
White Christmas was written by Irving Berlin, in New York, where Snow at Christmas is commonplace.
"The song White Christmas is undoubtedly the most famous and popular of all the Christmas songs. The music and lyrics for White Christmas were written in 1942 and originally featured in the movie Holiday Inn starring Bing Crosby. The lyrics of White Christmas struck a chord with the soldiers fighting in the Second World War and their families who were waiting for them back home. "
-- shamelessly lifted from t'interweb.