District of Columbia Frost Dates & Growing Zones by City
Washington is our only District of Columbia city with frost dates so far: typical (50%) last spring frost Mar 29, typical frost-free season 224 days.
The 2023 USDA hardiness map places them in zones 7b and 8a.
Dates come from the nearest NOAA station to each city that meets our quality rules, as the methodology explains.
| City | Last frost (50%) | First frost (50%) | Season (days, 50%) | Zone 2023 | Confidence | Planting calendar |
|---|---|---|---|---|---|---|
| Washington frost dates | Mar 29 | Nov 8 | 224 | 7b–8a | High | Washington planting calendar |
Station match, data and rules: methodology. Long-term odds, not a forecast.