Frost dates for 20004Washington, DC
The average last spring frost in Washington is March 24 and the average first fall frost is November 18, giving a typical growing season of about 241 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Mar 24
- Average first fall frost
- Nov 18
- Growing season
- 241 days
Safer after Apr 6 (1-in-10 risk)
Possible by Nov 5 (1-in-10 risk)
First frost typically in 15 days
Frost risk by date
NOAA reports frost dates as probabilities. The middle date is the average (a 50% chance). For spring, the 10% date is a safer planting date: frost after it happens in about 1 year in 10. Light frost (36°F) can damage tender plants; a hard freeze (28°F) kills most annuals.
| Temperature | Last spring: 90% / 50% / 10% chance | First fall: 10% / 50% / 90% chance | Growing season (50%) | Years with at least one |
|---|---|---|---|---|
| Light frost (36°F) | Mar 20 · Apr 3 · Apr 14 | Oct 26 · Nov 6 · Nov 20 | 216 days | 100% |
| Frost / freeze (32°F) | Mar 7 · Mar 24 · Apr 6 | Nov 5 · Nov 18 · Dec 6 | 241 days | 100% |
| Hard freeze (28°F) | Feb 23 · Mar 12 · Mar 26 | Nov 14 · Dec 3 · Dec 24 | 268 days | 100% |
Planting calendar for Washington
Planting windows from the University of Maryland Extension calendar, shifted to your average frost dates. Use them as a starting point and adjust for seed packet instructions and local conditions.
| Crop | Task | Window |
|---|---|---|
| Tomatoes | Start seeds indoors | Feb 21 – Apr 29 |
| Tomatoes | Transplant outdoors | Apr 9 – Jul 29 |
| Peppers | Start seeds indoors | Feb 21 – Mar 24 |
| Peppers | Transplant outdoors | Apr 23 – May 24 |
| Eggplant | Start seeds indoors | Mar 10 – Apr 8 |
| Eggplant | Transplant outdoors | Apr 23 – May 24 |
| Cucumbers | Sow outdoors | Apr 23 – Aug 8 |
| Summer squash | Sow outdoors | Apr 9 – May 24 |
| Winter squash & pumpkins | Sow outdoors | Apr 23 – May 24 |
| Snap beans | Sow outdoors | Apr 9 – Aug 31 |
| Sweet corn | Sow outdoors | Apr 9 – Jul 29 |
| Watermelon & cantaloupe | Sow outdoors | Apr 23 – May 24 |
| Okra | Sow outdoors | Apr 16 – May 9 |
| Peas | Sow outdoors (spring) | Feb 21 – Apr 8 |
| Potatoes | Plant outdoors (spring) | Feb 21 – Apr 23 |
| Onions | Start seeds indoors (spring) | Jan 10 – Feb 6 |
| Onions | Transplant outdoors (spring) | Mar 10 – Apr 8 |
| Broccoli | Start seeds indoors (spring) | Feb 3 – Mar 9 |
| Broccoli | Transplant outdoors (spring) | Mar 10 – Apr 8 |
| Broccoli | Start seeds indoors (fall) | Jul 19 – Jul 29 |
| Broccoli | Transplant outdoors (fall) | Aug 18 – Aug 29 |
| Cabbage | Start seeds indoors (spring) | Jan 24 – Feb 21 |
| Cabbage | Transplant outdoors (spring) | Feb 21 – Mar 24 |
| Cabbage | Start seeds indoors (fall) | Jul 9 – Aug 8 |
| Cabbage | Transplant outdoors (fall) | Aug 8 – Sep 8 |
| Leaf lettuce | Sow outdoors (spring) | Feb 21 – May 9 |
| Leaf lettuce | Sow outdoors (fall) | Aug 8 – Sep 24 |
| Spinach | Sow outdoors (spring) | Feb 14 – Mar 30 |
| Spinach | Sow outdoors (fall) | Aug 25 – Sep 29 |
| Radishes | Sow outdoors (spring) | Feb 21 – Apr 13 |
| Radishes | Sow outdoors (fall) | Aug 8 – Oct 9 |
| Kale | Sow outdoors (spring) | Mar 10 – Mar 30 |
| Kale | Sow outdoors (fall) | Aug 1 – Sep 8 |
| Carrots | Sow outdoors (spring) | Mar 24 – May 9 |
| Carrots | Sow outdoors (fall) | Jul 9 – Aug 24 |
| Garlic | Plant outdoors (fall) | Nov 8 – Dec 9 |
Where these dates come from
ZIP code 20004 is matched to the NOAA station Washington Reagan Ap, VA, 5 km away, at 10 ft elevation (0 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Washington Reagan Ap, VA (used) | 10 ft | Mar 24 | Nov 18 |
| Natl Arboretum Dc, MD | 50 ft | Mar 29 | Nov 8 |
| Dalecarlia Rsvr, MD | 150 ft | Apr 9 | Oct 31 |
| Oxon Hill, MD | 190 ft | Apr 3 | Nov 8 |
Frost dates near Washington
- Washington, DC 20535 · last Mar 24, first Nov 18
- Naval Anacost Annex, DC 20373 · last Mar 24, first Nov 18
- Washington Navy Yard, DC 20374 · last Mar 24, first Nov 18
- Arlington, VA 22243 · last Mar 24, first Nov 18
- Fort Myer, VA 22211 · last Apr 9, first Oct 31
- Alexandria, VA 22305 · last Mar 24, first Nov 18
- Mount Rainier, MD 20712 · last Mar 29, first Nov 8
- Brentwood, MD 20722 · last Mar 29, first Nov 8
Frequently asked questions
- When is the last frost in Washington, DC?
- For ZIP code 20004, the average last spring frost (32°F) is March 24, based on NOAA 1991-2020 climate normals for the Washington Reagan Ap, VA weather station. There is a 1-in-10 chance of a frost after April 6.
- When is the first frost in Washington, DC?
- The average first fall frost (32°F) is November 18. There is a 1-in-10 chance of frost by November 5, so tender plants are at risk from that point on.
- How long is the growing season in 20004?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 241 days long.
- Are these frost dates a forecast?
- No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.