Washington, DC Frost Dates
Average frost dates, USDA hardiness zone, and growing season length for Washington, District of Columbia.
Gardening in Washington
The nation's capital grows food between the monuments. DC's community garden scene is surprisingly robust — from plots along the Anacostia to rooftop gardens in Adams Morgan, federal workers and lifelong residents alike dig in the District's heavy clay.
Zone 7b with Potomac River moderation. The famous cherry blossoms are your planting clock — when the Tidal Basin blooms, it's time to start hardening off transplants. Summer humidity rivals Houston's, and the urban heat island effect makes downtown DC measurably warmer than the Virginia and Maryland suburbs.
Nationals fans and DC gardeners share a truth: eventually, something you've invested years in actually pays off. The Capitol grounds are immaculately maintained by the Architect of the Capitol, but the real horticultural soul of DC lives in the neighborhood community gardens of Brookland, Petworth, and Congress Heights.
What This Means for Washington Gardeners
The average last spring frost in Washington is around March 28, and the average first fall frost arrives around November 8. That gives you approximately 225 frost-free days to work with.
That's a generous season. You have time for full-size tomatoes, long-season peppers, and even watermelons without the anxiety of racing the frost. Start warm-season seeds indoors 6-8 weeks before your last frost to hit the ground running. Fall planting is your second opportunity — garlic, kale, lettuce, and broccoli all go in 8-10 weeks before your first frost for harvest into late autumn.
These dates are based on NOAA 30-year Climate Normal data for the Washington area. Your actual frost dates could shift 2-3 weeks in either direction in any given year. Learn more about our data sources.
What to Grow in Washington
Washington's 225-day growing season is generous — long enough for two full growing windows (spring and fall) with warm-season crops between them. You can grow the full range of vegetables, herbs, and flowers with proper timing. Focus on heat-tolerant varieties for midsummer and cool-season crops for extended fall harvests. Recommended starting points: tomatoes, peppers, beans, cucumbers, squash, garlic, kale, and sunflowers.
Enter your zip code for exact planting dates personalized to Washington.
More About Zone 7B
Washington is in USDA Hardiness Zone 7B, which means average annual extreme minimum temperatures between 5°F to 10°F. View the full Zone 7B planting guide.
Other Cities in District of Columbia
Frequently Asked Questions
These dates are based on NOAA's 30-year Climate Normal data for the Washington area. They represent historical averages, not predictions. In any given year, the actual last frost could be 2-3 weeks earlier or later. Microclimates within Washington (urban heat islands, hilltops, low-lying valleys) can also shift your local frost dates by a week or more.
Cool-season crops go in 3-4 weeks before your last frost (March 28). Warm-season crops wait until 2 weeks after. You have time for a fall round too — plant cool-season crops again in late summer for harvest into autumn. Enter your zip code for exact dates.