Frost dates for 20880Washington Grove, MD
The average last spring frost in Washington Grove is April 14 and the average first fall frost is October 29, giving a typical growing season of about 196 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 14
- Average first fall frost
- Oct 29
- Growing season
- 196 days
Safer after May 2 (1-in-10 risk)
Possible by Oct 13 (1-in-10 risk)
Last frost typically in 162 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 14 · Apr 28 · May 15 | Oct 5 · Oct 17 · Oct 31 | 171 days | 100% |
| Frost / freeze (32°F) | Mar 31 · Apr 14 · May 2 | Oct 13 · Oct 29 · Nov 12 | 196 days | 100% |
| Hard freeze (28°F) | Mar 18 · Apr 2 · Apr 16 | Oct 26 · Nov 8 · Nov 24 | 220 days | 100% |
Planting calendar for Washington Grove
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 14 – May 20 |
| Tomatoes | Transplant outdoors | Apr 30 – Jul 9 |
| Peppers | Start seeds indoors | Mar 14 – Apr 14 |
| Peppers | Transplant outdoors | May 14 – Jun 14 |
| Eggplant | Start seeds indoors | Mar 31 – Apr 29 |
| Eggplant | Transplant outdoors | May 14 – Jun 14 |
| Cucumbers | Sow outdoors | May 14 – Jul 19 |
| Summer squash | Sow outdoors | Apr 30 – Jun 14 |
| Winter squash & pumpkins | Sow outdoors | May 14 – Jun 14 |
| Snap beans | Sow outdoors | Apr 30 – Aug 11 |
| Sweet corn | Sow outdoors | Apr 30 – Jul 9 |
| Watermelon & cantaloupe | Sow outdoors | May 14 – Jun 14 |
| Okra | Sow outdoors | May 7 – May 30 |
| Peas | Sow outdoors (spring) | Mar 14 – Apr 29 |
| Potatoes | Plant outdoors (spring) | Mar 14 – May 14 |
| Onions | Start seeds indoors (spring) | Jan 31 – Feb 27 |
| Onions | Transplant outdoors (spring) | Mar 31 – Apr 29 |
| Broccoli | Start seeds indoors (spring) | Feb 24 – Mar 30 |
| Broccoli | Transplant outdoors (spring) | Mar 31 – Apr 29 |
| Broccoli | Start seeds indoors (fall) | Jun 29 – Jul 9 |
| Broccoli | Transplant outdoors (fall) | Jul 29 – Aug 9 |
| Cabbage | Start seeds indoors (spring) | Feb 14 – Mar 14 |
| Cabbage | Transplant outdoors (spring) | Mar 14 – Apr 14 |
| Cabbage | Start seeds indoors (fall) | Jun 19 – Jul 19 |
| Cabbage | Transplant outdoors (fall) | Jul 19 – Aug 19 |
| Leaf lettuce | Sow outdoors (spring) | Mar 14 – May 30 |
| Leaf lettuce | Sow outdoors (fall) | Jul 19 – Sep 4 |
| Spinach | Sow outdoors (spring) | Mar 7 – Apr 20 |
| Spinach | Sow outdoors (fall) | Aug 5 – Sep 9 |
| Radishes | Sow outdoors (spring) | Mar 14 – May 4 |
| Radishes | Sow outdoors (fall) | Jul 19 – Sep 19 |
| Kale | Sow outdoors (spring) | Mar 31 – Apr 20 |
| Kale | Sow outdoors (fall) | Jul 12 – Aug 19 |
| Carrots | Sow outdoors (spring) | Apr 14 – May 30 |
| Carrots | Sow outdoors (fall) | Jun 19 – Aug 4 |
| Garlic | Plant outdoors (fall) | Oct 19 – Nov 19 |
Where these dates come from
ZIP code 20880 is matched to the NOAA station Damascus 3 Ssw, MD, 14.9 km away, at 700 ft elevation (178 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Damascus 3 Ssw, MD (used) | 700 ft | Apr 14 | Oct 29 |
| Rockville 1 Ne, MD | 440 ft | Apr 1 | Nov 6 |
| Dalecarlia Rsvr, MD | 150 ft | Apr 9 | Oct 31 |
| Beltsville, MD | 145 ft | Apr 10 | Nov 1 |
Frost dates near Washington Grove
- Gaithersburg, MD 20877 · last Apr 14, first Oct 29
- Derwood, MD 20855 · last Apr 1, first Nov 6
- Bethesda, MD 20813 · last Apr 1, first Nov 6
- Rockville, MD 20848 · last Apr 1, first Nov 6
- Potomac, MD 20859 · last Apr 1, first Nov 6
- Germantown, MD 20875 · last Apr 1, first Nov 6
- Suburb Maryland Fac, MD 20897 · last Apr 1, first Nov 6
- Montgomery Village, MD 20886 · last Apr 14, first Oct 29
Frequently asked questions
- When is the last frost in Washington Grove, MD?
- For ZIP code 20880, the average last spring frost (32°F) is April 14, based on NOAA 1991-2020 climate normals for the Damascus 3 Ssw, MD weather station. There is a 1-in-10 chance of a frost after May 2.
- When is the first frost in Washington Grove, MD?
- The average first fall frost (32°F) is October 29. There is a 1-in-10 chance of frost by October 13, so tender plants are at risk from that point on.
- How long is the growing season in 20880?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 196 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.