Frost dates for 20749Fort Washington, MD
The average last spring frost in Fort Washington is April 3 and the average first fall frost is November 8, giving a typical growing season of about 217 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 3
- Average first fall frost
- Nov 8
- Growing season
- 217 days
Safer after Apr 15 (1-in-10 risk)
Possible by Oct 24 (1-in-10 risk)
First frost typically in 5 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) | Apr 1 · Apr 15 · May 2 | Oct 14 · Oct 27 · Nov 10 | 195 days | 100% |
| Frost / freeze (32°F) | Mar 19 · Apr 3 · Apr 15 | Oct 24 · Nov 8 · Nov 23 | 217 days | 100% |
| Hard freeze (28°F) | Mar 5 · Mar 21 · Apr 3 | Nov 5 · Nov 19 · Dec 8 | 244 days | 100% |
Planting calendar for Fort 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 | Mar 3 – May 9 |
| Tomatoes | Transplant outdoors | Apr 19 – Jul 19 |
| Peppers | Start seeds indoors | Mar 3 – Apr 3 |
| Peppers | Transplant outdoors | May 3 – Jun 3 |
| Eggplant | Start seeds indoors | Mar 20 – Apr 18 |
| Eggplant | Transplant outdoors | May 3 – Jun 3 |
| Cucumbers | Sow outdoors | May 3 – Jul 29 |
| Summer squash | Sow outdoors | Apr 19 – Jun 3 |
| Winter squash & pumpkins | Sow outdoors | May 3 – Jun 3 |
| Snap beans | Sow outdoors | Apr 19 – Aug 21 |
| Sweet corn | Sow outdoors | Apr 19 – Jul 19 |
| Watermelon & cantaloupe | Sow outdoors | May 3 – Jun 3 |
| Okra | Sow outdoors | Apr 26 – May 19 |
| Peas | Sow outdoors (spring) | Mar 3 – Apr 18 |
| Potatoes | Plant outdoors (spring) | Mar 3 – May 3 |
| Onions | Start seeds indoors (spring) | Jan 20 – Feb 16 |
| Onions | Transplant outdoors (spring) | Mar 20 – Apr 18 |
| Broccoli | Start seeds indoors (spring) | Feb 13 – Mar 19 |
| Broccoli | Transplant outdoors (spring) | Mar 20 – Apr 18 |
| Broccoli | Start seeds indoors (fall) | Jul 9 – Jul 19 |
| Broccoli | Transplant outdoors (fall) | Aug 8 – Aug 19 |
| Cabbage | Start seeds indoors (spring) | Feb 3 – Mar 3 |
| Cabbage | Transplant outdoors (spring) | Mar 3 – Apr 3 |
| Cabbage | Start seeds indoors (fall) | Jun 29 – Jul 29 |
| Cabbage | Transplant outdoors (fall) | Jul 29 – Aug 29 |
| Leaf lettuce | Sow outdoors (spring) | Mar 3 – May 19 |
| Leaf lettuce | Sow outdoors (fall) | Jul 29 – Sep 14 |
| Spinach | Sow outdoors (spring) | Feb 24 – Apr 9 |
| Spinach | Sow outdoors (fall) | Aug 15 – Sep 19 |
| Radishes | Sow outdoors (spring) | Mar 3 – Apr 23 |
| Radishes | Sow outdoors (fall) | Jul 29 – Sep 29 |
| Kale | Sow outdoors (spring) | Mar 20 – Apr 9 |
| Kale | Sow outdoors (fall) | Jul 22 – Aug 29 |
| Carrots | Sow outdoors (spring) | Apr 3 – May 19 |
| Carrots | Sow outdoors (fall) | Jun 29 – Aug 14 |
| Garlic | Plant outdoors (fall) | Oct 29 – Nov 29 |
Where these dates come from
ZIP code 20749 is matched to the NOAA station Oxon Hill, MD, 11 km away, at 190 ft elevation (76 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Oxon Hill, MD (used) | 190 ft | Apr 3 | Nov 8 |
| Upper Marlboro 3 Nnw, MD | 130 ft | Apr 9 | Oct 29 |
| Natl Arboretum Dc, MD | 50 ft | Mar 29 | Nov 8 |
| Washington Reagan Ap, VA | 10 ft | Mar 24 | Nov 18 |
Frost dates near Fort Washington
- Southern Md Facility, MD 20697 · last Apr 3, first Nov 8
- Lanham, MD 20703 · last Apr 3, first Nov 8
- Bowie, MD 20717 · last Apr 3, first Nov 8
- Riverdale, MD 20738 · last Apr 3, first Nov 8
- College Park, MD 20741 · last Apr 3, first Nov 8
- District Heights, MD 20753 · last Apr 3, first Nov 8
- Upper Marlboro, MD 20775 · last Apr 3, first Nov 8
- Capitol Heights, MD 20790 · last Apr 3, first Nov 8
Frequently asked questions
- When is the last frost in Fort Washington, MD?
- For ZIP code 20749, the average last spring frost (32°F) is April 3, based on NOAA 1991-2020 climate normals for the Oxon Hill, MD weather station. There is a 1-in-10 chance of a frost after April 15.
- When is the first frost in Fort Washington, MD?
- The average first fall frost (32°F) is November 8. There is a 1-in-10 chance of frost by October 24, so tender plants are at risk from that point on.
- How long is the growing season in 20749?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 217 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.