Last frost date in Dover, NH
In Dover, the last spring frost comes around May 3 in an average year. Wait until May 16 if you want 90% odds of no more frost. The first fall frost usually arrives about October 10, which leaves 158 frost-free days. An early freeze before September 27 happens one year in ten.
- Safe after (10% risk)
- May 16
- Average first frost
- Oct 10
- Frost-free season
- 158 days
- Hard freeze (28°F) ends
- Apr 20
Hard freeze likely Fri night, low 27°F
National Weather Service forecast, updated Oct 22, 12:57 UTC
- ThuOct 2233°possible frost
- FriOct 2327°hard freeze
- SatOct 2428°hard freeze
- SunOct 2533°possible frost
- MonOct 2639°
- TueOct 2734°possible frost
- WedOct 2835°possible frost
Planting calendar for Dover
Windows count forward or back from the average frost dates above. Click a crop for dates across New Hampshire.
TomatoesMay 10–May 24
PumpkinsMay 17–May 31
SunflowersMay 3–May 24
CucumbersMay 17–May 24
CornMay 10–May 24
Sweet potatoesMay 24–Jun 7
WatermelonMay 17–May 31
Green beansMay 10–May 31
ZucchiniMay 10–May 24
OkraMay 24–Jun 7
PeppersMay 17–May 31
BasilMay 10–May 24
Butternut squashMay 10–May 24
CantaloupeMay 17–May 31
EggplantMay 17–May 31
PotatoesApr 5–Apr 19
OnionsMar 22–Apr 12
CarrotsApr 12–May 17
LettuceApr 19–May 10
BroccoliApr 5–Apr 19
BeetsApr 5–May 17
PeasMar 22–Apr 5
CabbageApr 5–Apr 19
RadishesMar 29–May 10
Brussels sproutsApr 19–May 3
SpinachMar 22–Apr 12
CilantroApr 19–May 10
KaleApr 5–Apr 19
Collard greensApr 5–Apr 19
TurnipsApr 5–Apr 19
DillMay 3–May 17
CeleryMay 10–May 17
CauliflowerApr 19–May 3
LeeksApr 19–May 3
Swiss chardApr 19–May 17
ParsleyApr 19–May 10
Tulip bulbsSep 26–Oct 31
GarlicSep 19–Oct 24
Daffodil bulbsSep 12–Oct 24
StrawberriesApr 5–Apr 19
AsparagusApr 5–Apr 19Frost probabilities
| Threshold | Spring, 90% chance later | Spring, 50% | Spring, 10% | Fall, 10% chance earlier | Fall, 50% | Fall, 90% |
|---|---|---|---|---|---|---|
| Light frost, 32°F | Apr 23 | May 3 | May 16 | Sep 27 | Oct 10 | Oct 25 |
| Hard freeze, 28°F | Apr 6 | Apr 20 | May 3 | Oct 7 | Oct 23 | Nov 6 |
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 Durham 2 N (USW00054794) sits 2.4 miles from the center of Dover at 119 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 Dover, NH?
The average last frost date in Dover is May 3, based on NOAA 1991–2020 climate normals. There is a 10% chance of frost after May 16.
When is the first frost in Dover?
The first frost in fall usually comes around October 10. One year in ten it arrives before September 27.
How long is the growing season in Dover?
About 158 days between the average last and first frost.
When should I plant tomatoes in Dover?
Plant tomato seedlings outside from May 10 to May 24. Start seeds indoors six to eight weeks earlier.
Nearby in New Hampshire
- RochesterApr 30
- PortsmouthMay 4
- DerryApr 30
- ManchesterApr 30
- ConcordMay 8
- NashuaApr 29
- KeeneMay 14