Frost dates for 19977Smyrna, DE
The average last spring frost in Smyrna is April 4 and the average first fall frost is November 4, giving a typical growing season of about 214 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 4
- Average first fall frost
- Nov 4
- Growing season
- 214 days
Safer after Apr 17 (1-in-10 risk)
Possible by Oct 23 (1-in-10 risk)
First frost typically in 1 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 3 · Apr 17 · May 5 | Oct 12 · Oct 25 · Nov 6 | 191 days | 100% |
| Frost / freeze (32°F) | Mar 22 · Apr 4 · Apr 17 | Oct 23 · Nov 4 · Nov 18 | 214 days | 100% |
| Hard freeze (28°F) | Mar 8 · Mar 25 · Apr 5 | Nov 3 · Nov 16 · Dec 3 | 238 days | 100% |
Planting calendar for Smyrna
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 4 – May 10 |
| Tomatoes | Transplant outdoors | Apr 20 – Jul 15 |
| Peppers | Start seeds indoors | Mar 4 – Apr 4 |
| Peppers | Transplant outdoors | May 4 – Jun 4 |
| Eggplant | Start seeds indoors | Mar 21 – Apr 19 |
| Eggplant | Transplant outdoors | May 4 – Jun 4 |
| Cucumbers | Sow outdoors | May 4 – Jul 25 |
| Summer squash | Sow outdoors | Apr 20 – Jun 4 |
| Winter squash & pumpkins | Sow outdoors | May 4 – Jun 4 |
| Snap beans | Sow outdoors | Apr 20 – Aug 17 |
| Sweet corn | Sow outdoors | Apr 20 – Jul 15 |
| Watermelon & cantaloupe | Sow outdoors | May 4 – Jun 4 |
| Okra | Sow outdoors | Apr 27 – May 20 |
| Peas | Sow outdoors (spring) | Mar 4 – Apr 19 |
| Potatoes | Plant outdoors (spring) | Mar 4 – May 4 |
| Onions | Start seeds indoors (spring) | Jan 21 – Feb 17 |
| Onions | Transplant outdoors (spring) | Mar 21 – Apr 19 |
| Broccoli | Start seeds indoors (spring) | Feb 14 – Mar 20 |
| Broccoli | Transplant outdoors (spring) | Mar 21 – Apr 19 |
| Broccoli | Start seeds indoors (fall) | Jul 5 – Jul 15 |
| Broccoli | Transplant outdoors (fall) | Aug 4 – Aug 15 |
| Cabbage | Start seeds indoors (spring) | Feb 4 – Mar 4 |
| Cabbage | Transplant outdoors (spring) | Mar 4 – Apr 4 |
| Cabbage | Start seeds indoors (fall) | Jun 25 – Jul 25 |
| Cabbage | Transplant outdoors (fall) | Jul 25 – Aug 25 |
| Leaf lettuce | Sow outdoors (spring) | Mar 4 – May 20 |
| Leaf lettuce | Sow outdoors (fall) | Jul 25 – Sep 10 |
| Spinach | Sow outdoors (spring) | Feb 25 – Apr 10 |
| Spinach | Sow outdoors (fall) | Aug 11 – Sep 15 |
| Radishes | Sow outdoors (spring) | Mar 4 – Apr 24 |
| Radishes | Sow outdoors (fall) | Jul 25 – Sep 25 |
| Kale | Sow outdoors (spring) | Mar 21 – Apr 10 |
| Kale | Sow outdoors (fall) | Jul 18 – Aug 25 |
| Carrots | Sow outdoors (spring) | Apr 4 – May 20 |
| Carrots | Sow outdoors (fall) | Jun 25 – Aug 10 |
| Garlic | Plant outdoors (fall) | Oct 25 – Nov 25 |
Where these dates come from
ZIP code 19977 is matched to the NOAA station Dover, DE, 18.3 km away, at 30 ft elevation (10 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Dover, DE (used) | 30 ft | Apr 4 | Nov 4 |
| Seabrook Farms, NJ | 104 ft | Apr 10 | Nov 1 |
| Chestertown, MD | 40 ft | Apr 3 | Nov 5 |
| Wilmington New Castle Co Ap, DE | 79 ft | Apr 7 | Nov 1 |
Frost dates near Smyrna
- Cheswold, DE 19936 · last Apr 4, first Nov 4
- Clayton, DE 19938 · last Apr 4, first Nov 4
- Kenton, DE 19955 · last Apr 4, first Nov 4
- Townsend, DE 19734 · last Apr 4, first Nov 4
- Dover, DE 19904 · last Apr 4, first Nov 4
- Hartly, DE 19953 · last Apr 4, first Nov 4
- Odessa, DE 19730 · last Apr 7, first Nov 1
- Massey, MD 21650 · last Apr 3, first Nov 5
Frequently asked questions
- When is the last frost in Smyrna, DE?
- For ZIP code 19977, the average last spring frost (32°F) is April 4, based on NOAA 1991-2020 climate normals for the Dover, DE weather station. There is a 1-in-10 chance of a frost after April 17.
- When is the first frost in Smyrna, DE?
- The average first fall frost (32°F) is November 4. There is a 1-in-10 chance of frost by October 23, so tender plants are at risk from that point on.
- How long is the growing season in 19977?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 214 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.