Last frost date in Wilmington, DE
In Wilmington, the last spring frost comes around April 7 in an average year. Wait until April 24 if you want 90% odds of no more frost. The first fall frost usually arrives about November 4, which leaves 209 frost-free days. An early freeze before October 21 happens one year in ten.
- Safe after (10% risk)
- Apr 24
- Average first frost
- Nov 4
- Frost-free season
- 209 days
- Hard freeze (28°F) ends
- Mar 29
No frost in the next 7 nights
National Weather Service forecast, updated Oct 22, 12:57 UTC
- ThuOct 2245°
- FriOct 2337°
- SatOct 2438°
- SunOct 2541°
- MonOct 2648°
- TueOct 2747°
- WedOct 2848°
Planting calendar for Wilmington
Windows count forward or back from the average frost dates above. Click a crop for dates across Delaware.
TomatoesApr 14–Apr 28
PumpkinsApr 21–May 5
SunflowersApr 7–Apr 28
CucumbersApr 21–Apr 28
CornApr 14–Apr 28
Sweet potatoesApr 28–May 12
WatermelonApr 21–May 5
Green beansApr 14–May 5
ZucchiniApr 14–Apr 28
OkraApr 28–May 12
PeppersApr 21–May 5
BasilApr 14–Apr 28
Butternut squashApr 14–Apr 28
CantaloupeApr 21–May 5
EggplantApr 21–May 5
PotatoesMar 10–Mar 24
OnionsFeb 24–Mar 17
CarrotsMar 17–Apr 21
LettuceMar 24–Apr 14
BroccoliMar 10–Mar 24
BeetsMar 10–Apr 21
PeasFeb 24–Mar 10
CabbageMar 10–Mar 24
RadishesMar 3–Apr 14
Brussels sproutsMar 24–Apr 7
SpinachFeb 24–Mar 17
CilantroMar 24–Apr 14
KaleMar 10–Mar 24
Collard greensMar 10–Mar 24
TurnipsMar 10–Mar 24
DillApr 7–Apr 21
CeleryApr 14–Apr 21
CauliflowerMar 24–Apr 7
LeeksMar 24–Apr 7
Swiss chardMar 24–Apr 21
ParsleyMar 24–Apr 14
Tulip bulbsOct 21–Nov 25
GarlicOct 14–Nov 18
Daffodil bulbsOct 7–Nov 18
StrawberriesMar 10–Mar 24
AsparagusMar 10–Mar 24Frost probabilities
| Threshold | Spring, 90% chance later | Spring, 50% | Spring, 10% | Fall, 10% chance earlier | Fall, 50% | Fall, 90% |
|---|---|---|---|---|---|---|
| Light frost, 32°F | Mar 26 | Apr 7 | Apr 24 | Oct 21 | Nov 4 | Nov 19 |
| Hard freeze, 28°F | Mar 13 | Mar 29 | Apr 10 | Nov 1 | Nov 15 | Dec 2 |
Read the spring 10% column as the date after which only one year in ten still gets frost. That is the safer date for tomatoes, peppers and basil.
Where these numbers come from
NOAA station Wilmington Porter Rsch (USC00079605) sits 2.7 miles from the center of Wilmington at 270 feet. Its averages cover 1991 to 2020. Low spots, valleys and open fields can keep getting frost a week or two after the station stops; city centers and lakeshores usually get less of it.
Questions
When is the last frost in Wilmington, DE?
The average last frost date in Wilmington is April 7, based on NOAA 1991–2020 climate normals. There is a 10% chance of frost after April 24.
When is the first frost in Wilmington?
The first frost in fall usually comes around November 4. One year in ten it arrives before October 21.
How long is the growing season in Wilmington?
About 209 days between the average last and first frost.
When should I plant tomatoes in Wilmington?
Plant tomato seedlings outside from April 14 to April 28. Start seeds indoors six to eight weeks earlier.
Nearby in Delaware
- BearApr 7
- NewarkApr 7
- MiddletownApr 7
- DoverApr 4