Census ZIP Code Tabulation Area
Will ZIP 20854 have a white Christmas?
Snow-on-the-ground odds near Potomac, MD, for December 25, 2026.
The historical picture
The validated 1991–2020 spatial model indicates an estimated 8% chance of at least one inch of snow on the ground at this ZCTA’s Census internal point.
ACS population
50,498
Land area
33.85 sq mi
Nearest station
9 mi
3DEP elevation
381 ft
Climate period
1991–2020
This is a Census ZCTA, not a USPS delivery-route boundary. Its internal point is 2 miles from Potomac. The estimate retains all four NOAA source stations and their interpolation weights.
Frequently asked questions
- Will ZIP 20854 have a white Christmas?
- Its validated 1991–2020 historical estimate is 8%, or about about 1 year in 10. Inside the forecast window, live ensemble guidance is blended with that history.
- Is this the exact USPS ZIP boundary?
- No. The Census Bureau creates ZIP Code Tabulation Areas to approximate the geography of USPS ZIP Codes. USPS delivery routes can change and do not form a permanent national polygon dataset.