White Christmas Probability Calculator
Check the historical probability of a white Christmas for your city. Based on NOAA climate data, find snow depth and igloo feasibility on Christmas Day.
About This Calculator
The White Christmas Probability Calculator helps you find out the historical likelihood of waking up to snow on Christmas morning. Select a major city across the US, Canada, or UK to see the probability of at least 1 inch of snow on the ground on December 25, based on 30-year climate normals from NOAA and Environment and Climate Change Canada.
For each city, the calculator displays the historical white Christmas probability (percentage of years with snow cover on Christmas Day), the typical snow depth on December 25, and whether the snow is deep enough to build an igloo (at least 10 inches). You can also enter custom probability and snow depth values for any location worldwide.
Regional Notes
United States: NOAA defines a white Christmas as at least 1 inch of snow on the ground. The highest probabilities are in Alaska, the Upper Midwest, the Northeast, and the Rocky Mountains. The 1981-2010 climate normals are the standard reference period used by NOAA.
Canada: Environment and Climate Change Canada provides probability data for major Canadian cities. Overall, Canadian cities have approximately 68% historical probability of a white Christmas, with Prairie and Northern cities exceeding 90%.
United Kingdom: The UK Met Office uses the same 1-inch threshold. White Christmases are rare in southern England (about 5% probability in London) but more common in Scotland, where Edinburgh has roughly 18% historical probability. The last widespread UK white Christmas was in 2010.
Frequently Asked Questions
What is a white Christmas?
A white Christmas is officially defined as at least 1 inch (2.5 cm) of snow on the ground on December 25. The National Oceanic and Atmospheric Administration (NOAA) and UK Met Office both use this threshold to define meteorological white Christmas conditions.
What cities have the highest chance of a white Christmas?
North American cities with the highest historical probability include Winnipeg (98%), Anchorage (90%), Calgary (75%), Minneapolis (74%), and Montreal (70%). In the UK, Edinburgh (18%) and Glasgow (15%) have the highest chances among major cities.
How is white Christmas probability calculated?
The probability is based on 30-year climate normals from NOAA (1981-2020 for US cities) and Environment and Climate Change Canada for Canadian cities. It represents the historical percentage of years with at least 1 inch of snow on the ground on Christmas Day.
Can you build an igloo with the snow?
Building a traditional igloo requires a snow depth of at least 10 inches (25 cm) of compacted snow. If your city's typical snow depth on Christmas Day is 10 inches or more, an igloo is theoretically feasible.
What was the most widespread white Christmas in US history?
Christmas 2017 was one of the most widespread white Christmases in the lower 48 states in 15 years. Last-minute snowstorms brought snow cover to a large portion of the US, giving many southern cities a rare white Christmas.
How does climate change affect white Christmas probability?
Rising global temperatures have reduced snow cover and shifted snowfall patterns. Many traditional snow-belt cities are experiencing fewer white Christmases than they did 30 years ago. NOAA tracks these changes through updated 30-year climate normals.
What is the difference between snow on the ground and snowfall?
Snow on the ground (snow depth) measures accumulated snow cover, while snowfall measures fresh precipitation. A white Christmas requires at least 1 inch of snow on the ground by Christmas morning, which can come from snow that fell days earlier.
Does it snow everywhere in Canada on Christmas?
No. While cities like Winnipeg and Calgary have very high probabilities (98% and 75%), Vancouver on the Pacific coast only has about a 10% chance of a white Christmas due to its maritime climate. Overall, Canadian cities have about a 68% average chance according to historical data.