District of Columbia frost dates

Across District of Columbia, the average last spring frost is around April 10 and the average first fall frost around October 25 — roughly 198 frost-free days. USDA zones 7a, 7b, 8a.

Risk you accept	Last spring frost by	First fall frost by
Cautious (~10%)	April 24	October 11
Average (~50%)	April 10	October 25
Gambler (~90%)	March 27	November 8

→ Turn these into sowing dates with the District of Columbia planting calendar, or look up an exact ZIP code.

Statewide average from NOAA/NCEI freeze normals. Cautious/gambler dates are about two weeks either side of the average.