White Christmas Predictor
Find out the historical probability of having a White Christmas in your city. Select a location to see the chances of having at least one inch (or 2.5 cm) of snow on the ground on December 25th.
Check Your City's Chances
The Science Behind the Snowflake: Predicting a White Christmas
For millions of people, waking up to a blanket of fresh snow on Christmas morning is the ultimate holiday gift. It is a scene straight out of a Norman Rockwell painting, popularized by songs, movies, and literature. But beyond the nostalgia lies a complex web of meteorology, geography, and climate science. This calculator uses historical climate data from the National Oceanic and Atmospheric Administration (NOAA) to determine the statistical likelihood of this event.
Defining the "White Christmas"
In meteorological terms, a "White Christmas" is strictly defined as having at least 1 inch (2.5 cm) of snow on the ground at 7:00 AM local time on December 25th. It does not technically require snow to be falling from the sky on that day. This distinction is important because a heavy snowfall on Christmas Eve that sticks around qualifies, while flurries on Christmas Day that melt upon contact do not.
The Role of Geography
Location is everything. Cities shielded by mountain ranges (like Seattle) or warmed by ocean currents (like London) have significantly lower probabilities than inland cities at similar latitudes.
- Lake Effect Snow: Cities like Buffalo and Syracuse have high probabilities due to the "Lake Effect," where cold air moves over warmer lake waters, picking up moisture that freezes and falls as snow on the leeward shores.
- Elevation: For every 1,000 feet you ascend, the temperature drops by about 3-5°F. This is why Denver (The Mile High City) has a moderate chance, while nearby Aspen is almost guaranteed snow.
Climate Patterns: El Niño and La Niña
Annual weather patterns play a huge spoiler role.
- El Niño: Typically brings warmer, drier winters to the Northern US, reducing the chances of a White Christmas in places like the Midwest and Northeast.
- La Niña: Often pushes the jet stream northward, potentially bringing colder, wetter conditions to the Pacific Northwest and the Northern Plains, boosting snow chances.
The Impact of Climate Change
Historical data serves as a guide, but trends are shifting. Analysis shows that the "snow line"—the geographic boundary where snow is likely—is slowly moving northward. Cities that were once reliable bets for a White Christmas, such as St. Louis or Philadelphia, have seen their probabilities dip slightly over the last three decades as December temperatures rise.
Frequently Asked Questions (FAQ)
It is incredibly rare, but yes. In 1989, a historic cold snap brought snow as far south as Jacksonville on Christmas weekend. However, for statistical purposes, the probability remains effectively 0%.
Of major metropolitan areas, Minneapolis, MN, consistently ranks at the top with a probability of around 75-80%. For smaller cities, places like Marquette, MI, or Aspen, CO, boast probabilities near 100%.
The 1-inch threshold is used by NOAA and other weather services because it represents a measurable, impactful amount of snow. A "trace" of snow (less than 0.1 inch) is often visually indistinguishable from frost and does not impact travel or activities.
No. This tool provides climatological probability (what usually happens), not a weather forecast (what is happening this week). For a specific forecast, you need to check weather models about 7-10 days before the holiday.