Last spring frost
Mar 24
Frost Dates for Washington, DC
First fall frost
Nov 18
Growing season
241 days
Hardiness zone
8a
In an average year around Washington, DC, the last spring frost (32°F) is about Mar 24 and the first fall frost is about Nov 18, giving roughly a 241-day growing season. To be safe most years, wait until Mar 7 before setting out tender plants.
Last spring frost
Dates the last frost of spring typically ends. Plant tender crops after the risk has passed for your comfort level.
| Frost intensity | Early (10%) | Average (50%) | Late (90%) |
|---|---|---|---|
| Light (36°F) | Apr 14 | Apr 3 | Mar 20 |
| Freeze (32°F) | Apr 6 | Mar 24 | Mar 7 |
| Hard (28°F) | Mar 26 | Mar 12 | Feb 23 |
| Severe (24°F) | Mar 19 | Mar 2 | Feb 8 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 14 | Apr 11 | Apr 7 | Apr 5 | Apr 3 | Apr 1 | Mar 29 | Mar 25 | Mar 20 |
| 32°F | Apr 6 | Apr 2 | Mar 30 | Mar 27 | Mar 24 | Mar 21 | Mar 17 | Mar 14 | Mar 7 |
| 28°F | Mar 26 | Mar 21 | Mar 18 | Mar 15 | Mar 12 | Mar 8 | Mar 5 | Mar 1 | Feb 23 |
| 24°F | Mar 19 | Mar 14 | Mar 9 | Mar 5 | Mar 2 | Feb 27 | Feb 22 | Feb 16 | Feb 8 |
| 20°F | Mar 7 | Mar 2 | Feb 26 | Feb 20 | Feb 15 | Feb 8 | Feb 3 | Jan 29 | Jan 16 |
| 16°F | Feb 24 | Feb 16 | Feb 9 | Feb 3 | Jan 31 | Jan 27 | Jan 21 | Jan 15 | Jan 9 |
First fall frost
Dates the first frost of fall typically arrives. Count back by a crop's days-to-maturity to know your planting cutoff.
| Frost intensity | Early (10%) | Average (50%) | Late (90%) |
|---|---|---|---|
| Light (36°F) | Oct 26 | Nov 6 | Nov 20 |
| Freeze (32°F) | Nov 5 | Nov 18 | Dec 6 |
| Hard (28°F) | Nov 14 | Dec 3 | Dec 24 |
| Severe (24°F) | Dec 1 | Dec 22 | Jan 12 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 26 | Oct 30 | Nov 2 | Nov 4 | Nov 6 | Nov 9 | Nov 12 | Nov 15 | Nov 20 |
| 32°F | Nov 5 | Nov 8 | Nov 12 | Nov 15 | Nov 18 | Nov 21 | Nov 25 | Nov 30 | Dec 6 |
| 28°F | Nov 14 | Nov 21 | Nov 26 | Nov 30 | Dec 3 | Dec 6 | Dec 11 | Dec 17 | Dec 24 |
| 24°F | Dec 1 | Dec 7 | Dec 11 | Dec 17 | Dec 22 | Dec 25 | Dec 30 | Jan 3 | Jan 12 |
| 20°F | Dec 13 | Dec 21 | Dec 26 | Jan 1 | Jan 4 | Jan 8 | Jan 13 | Jan 20 | Jan 29 |
| 16°F | Dec 26 | Jan 1 | Jan 6 | Jan 10 | Jan 14 | Jan 18 | Jan 24 | Jan 28 | Feb 5 |
Growing season is measured at 32°F with about 50% probability. Hardiness zone from the 2023 USDA map; frost normals from NOAA 1991-2020.
Where this data comes from
@endif These dates are computed from the nearest official weather station with long-term records: Washington Reagan Ap, Va, about 1.6 miles away@if(!empty($station['elevation_ft'])), at 10 ft elevation. The further the station and the greater the elevation difference from your yard, the more your local frost timing can vary.
How we calculate these dates
Frost and freeze dates come from the NOAA 1991–2020 U.S. Climate Normals, the National Oceanic and Atmospheric Administration's 30-year averages for each weather station. A date shown at the 50% level is the median: in half of years the frost falls on or before it. The 10% and 90% columns show the early and late ends of the range, so you can plant on the odds you're comfortable with. These are long-term averages, not a forecast for this year - always check your local outlook before planting.
Source: NOAA National Centers for Environmental Information, 1991–2020 Climate Normals (public domain). Harman is not affiliated with or endorsed by NOAA.
Frequently asked questions
When is the last frost in Washington, DC?
On average, the last spring frost (32°F) around Washington, DC is about Mar 24. In cooler years it can run later, so for a safer bet many gardeners wait until Mar 7.
When is the first frost in the fall?
The first fall frost around Washington, DC typically arrives about Nov 18. Count back by a crop's days to maturity to find the latest date you can plant it.
When can I plant tomatoes and other tender crops?
Tender crops like tomatoes, peppers and basil are damaged by frost, so wait until the last spring frost has passed - around Mar 24 on average, or Mar 7 to be safe most years.
How long is the growing season here?
The frost-free growing season (between the last spring and first fall 32°F frost) is about 241 days in a typical year.
Are these dates a forecast for this year?
No. They are 30-year averages from the NOAA 1991–2020 Climate Normals, not a prediction for the current year. Use them for planning and always check your local weather forecast before planting or protecting crops.
Local weather for 20319 Planting calendar → District of Columbia frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026