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Frost Dates in Washington, DC
First and last frost dates across Washington, DC, computed from 17 NOAA weather stations (1991–2020 climate normals). Your exact date depends on your city and microclimate — use the ZIP lookup on the main tool for a station-specific answer. No NOAA freeze stations fall inside the District itself — the figures below use 17 stations within 60 miles, in Maryland and Virginia. Gardeners in the city itself: the Washington row below (nearest station Washington Reagan) shows a median last spring frost of Mar 24.
Last spring frost
Apr 10
area-wide median · range Mar 23–Apr 22
First fall frost
Nov 1
area-wide median · range Oct 20–Nov 20
Growing season
202 days
median · range 179–241
Stations used
17
NOAA 1991–2020 normals
Frost dates by city
Median dates from the nearest NOAA station to each city. The "cautious" date is the 10% spring value — planting after it means only a ~10% chance of a later frost.
| City | Nearest station | Last spring frost | First fall frost | Growing season | Safe transplant |
|---|---|---|---|---|---|
| Washington | Washington Reagan Natl Ap (VA) · 3 mi | Mar 24 (cautious: Apr 6) | Nov 18 | 241 days | Apr 7 |
How frost varies across Washington, DC
Spring frost timing spans about 30 days across the Washington, DC area. Annapolis US Naval Academy, in the eastern part of the DC area typically sees its last spring frost around March 23, while Emmitsburg, in the northern part of the DC area doesn't clear frost until about April 22. Within any city, low spots and valleys run colder than the station average; areas near buildings and pavement run warmer.
When to plant in Washington, DC
As a rule of thumb, cool-season crops (lettuce, peas, spinach) can go in 2–4 weeks before your last spring frost; warm-season transplants (tomatoes, peppers) should wait about 2 weeks after it — around April 24 for the area-wide median. Check your city's row above rather than the area-wide median: a 30-day area-wide spread makes the city-level date the one that matters.
These are climate normals (what's typical), not forecasts. For the current year, watch the 10-day forecast around your planting date.
How this is computed
Area-wide medians are the median of the 17 NOAA stations' median frost dates — half the stations run earlier, half later. City rows use the nearest station with 30-year freeze records. Dates are 32°F freeze probabilities from NOAA NCEI 1991–2020 U.S. Climate Normals; nothing is estimated or interpolated.
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Frequently asked questions
When is the last frost date in Washington, DC?
The area-wide median last spring frost is April 10, but it ranges from March 23 to April 22 depending on where in the Washington, DC area you are. Use your city's row in the table above, or the ZIP lookup on the main tool, for a station-specific date.
When can I plant tomatoes outside in Washington, DC?
Warm-season transplants like tomatoes should wait about two weeks after your last spring frost — around April 24 for the area-wide median. Your city may differ by weeks; check the "safe transplant" column in the city table.
How long is the growing season in Washington, DC?
The median growing season across 17 NOAA stations is 202 days, ranging from 179 to 241 days by location.
Why do frost dates vary so much within Washington, DC?
Frost timing follows latitude, elevation, and local terrain. Across Washington, DC, last spring frost dates span about 30 days — from around March 23 near Annapolis US Naval Academy to April 22 near Emmitsburg. Microclimates (low spots, valleys, urban heat) shift dates further at the garden level.
Where does this data come from?
All frost dates are computed from the NOAA National Centers for Environmental Information 1991–2020 U.S. Climate Normals freeze data (public domain), using each station's 32°F freeze probability statistics. No dates are estimated or interpolated.