White Christmas

White Christmas refers to the presence of snow on Christmas Day. This phenomenon is most common in the northern countries of the Northern Hemisphere. Because December is in the middle of the Southern Hemisphere summer, white Christmases there are extremely rare, except in Antarctica, in the Southern Alps of New Zealand's South Island, and in parts of the Andes in South America.


The definition of "White Christmas" varies. In most countries, it simply means that the ground is covered by snow at Christmas, but some countries have more strict definitions. In the United States, the official definition of a white Christmas is that there has to be a snow depth of at least 1 inch (2.5 cm) on Christmas morning, and in Canada the official definition is that there has to be more than 2 cm (0.79 in) on the ground on Christmas Day. In the United Kingdom, although for many a white Christmas simply means a complete covering of snow on Christmas Day, the official definition by the British Met Office and British bookmakers is for snow to be observed falling, however little, (even if it melts before it reaches the ground) in the 24 hours of 25 December. Consequently, according to the Met Office and British bookmakers, even 3 ft (91 cm) of snow on the ground at Christmas, because of a heavy snow fall a few days before, will not constitute a white Christmas, but a few snow flakes mixed with rain will, even if they never reach the ground. In the United Kingdom the most likely place to see snowfall on a Christmas Day is in North and North Eastern Scotland, in Aberdeen, Aberdeenshire or the Highlands.


In most parts of Canada it is likely to have a white Christmas in most years, except for the coast and southern interior valleys of British Columbia, southern Alberta, southern Ontario, and parts of Atlantic Canada - in those places Christmas without snow is not uncommon in warmer years, with the British Columbia coast the least likely place to have a white Christmas.

In the United States, there is often snow on the ground at Christmas in the northern states, except in the Pacific Northwest. Some of the least likely white Christmases that have happened include the 2004 Christmas Eve Snowstorm, which brought the first white Christmas in 50 years to New Orleans and caused the first recorded white Christmas in Houston, Texas. The 2004 storm also brought the first measurable snow of any kind since 1895 to Brownsville, Texas, and its twin city of Matamoros, Mexico. The Florida winter storm of 1989 also occurred immediately before Christmas causing a white Christmas for cities like Pensacola and Jacksonville. The same storm buried Wilmington, North Carolina and the rest of Southeastern North Carolina under 15 in (38 cm) of snow.
In the United States the notion of a white Christmas is often associated in the American popular consciousness with a Christmas celebration that includes traditional observances in the company of friends and family. White Christmas is an Irving Berlin song reminiscing about an old-fashioned Christmas setting.