What Counts as a White Christmas in the United States
A white Christmas in the United States is commonly understood as having at least 1 inch (2.5 cm) of snow on the ground at or near sunrise on December 25. This definition is widely used by the National Weather Service and NOAA to standardize observations and climate records. It focuses on measurable snow depth rather than snowfall during the day, which can vary with timing and local conditions. The measure is used for long term climate comparisons across cities and states, though local forecasts often reference any snow on the ground on Christmas Day.
How Often the United States Has a White Christmas
Historical data show wide regional variation in the likelihood of a white Christmas. In the northern tier of states, probabilities are high; in the South, they are very low or nearly zero. These differences reflect climate, latitude, and elevation more than year to year fluctuations.
| Region or City | Approximate Historical Probability | Verification Source and Period |
|---|---|---|
| Anchorage, Alaska | Above 80% | NOAA climate averages, 1991–2020 normals |
| Minneapolis, Minnesota | 60–70% | NOAA and NCEI climate summaries, 1991–2020 normals |
| New York City | 25–40% | NOAA and NCEI climate summaries, 1991–2020 normals |
| Chicago, Illinois | 40–50% | NOAA and NCEI climate summaries, 19 normals (1991–2020) |
| Los Angeles, California | Near 0% to low single digits | NOAA climate averages, 1991–2020 normals |
| Houston, Texas | Low single digits to near 0% | NOAA climate averages, normals and summaries |
Probabilities are based on historical climate normals (typically a 30 year baseline such as 1991–2020) and may not predict any specific year with certainty.
Regional Variation and Geography
The likelihood of a white Christmas increases with latitude, elevation, and distance from moderating coastal influences. Mountain states and the interior Northeast often see deeper and more persistent snowpack by late December, while coastal and southern regions experience milder temperatures that reduce snow frequency. When snow does occur in southern areas, it is usually light, short lived, and less likely to meet the 1 inch depth definition used for official climate records.
Key Geographic Patterns
- Northern Rockies and Pacific Northwest: High frequency; persistent mountain snowpack often reaches valley towns by Christmas.
- Upper Midwest and interior New England: Regular white Christmases driven by cold continental air and lake effect snow.
- Mid-Atlantic and urban Northeast: Moderate to low odds; snowstorms can occur but milder temperatures often lead to mixed precipitation or rain.
- Southern and Gulf Coast states: Very low odds; when snow occurs, it is typically brief and does not accumulate to official white Christmas levels.
White Christmas vs. Other Snow Measures
It is useful to distinguish between a white Christmas (snow on the ground on December 25) and other related measures such as snowfall amount or the number of days with snow on the ground. A location can receive meaningful snowfall in December yet not meet the white Christmas threshold if temperatures rise or winds redistribute the snow. Conversely, a white Christmas can occur even when little or no fresh snow falls on Christmas Day itself, provided a deep enough snowpack persists from earlier storms.
Reliable Sources for Historical and Forecast Data
For historical probabilities and climate normals, NOAA National Centers for Environmental Information (NCEI) provides long term datasets and station summaries. Local National Weather Service offices issue forecasts and advisories that reflect current model guidance and on the ground observations. These sources use consistent definitions and quality controlled datasets, supporting reliable comparisons across years and regions.
Interpreting Annual Variability and Long Term Trends
Year to year conditions vary with large scale patterns such as El Niño and La Niña, which can favor warmer or colder and wetter or drier Decembers in different regions. On multi decade timescales, shifts in average winter temperatures and snowpack depth may alter the frequency of white Christmases, particularly in parts of the central and eastern United States. Official climate records document these patterns while emphasizing that any single year can deviate substantially from the long term average. Planning around the likelihood of a white Christmas is most useful when viewed as a historical probability rather than a fixed annual outcome.
Practical Takeaways
- A white Christmas in the U.S. is defined as at least 1 inch of snow on the ground on December 25.
- Probabilities vary strongly by region, from near certainty in parts of Alaska and the Upper Midwest to near zero in the Southeast and coastal California.
- Historical climate normals provide a reliable basis for understanding long term likelihood, though yearly outcomes can differ.
- Snowfall on Christmas Day and snow depth on the ground are distinct measures; a white Christmas depends on measured snow depth at dawn.
- Local National Weather Service forecasts and NOAA climate data are the best sources for current outlooks and historical context.