Last frost date in Marlborough, MA
The average last frost in Marlborough is May 2. By May 16 the chance of another 32°F night drops to 1 in 10. The first fall frost usually arrives about October 6, which leaves 156 frost-free days. An early freeze before September 25 happens one year in ten.
- Safe after (10% risk)
- May 16
- Average first frost
- Oct 6
- Frost-free season
- 156 days
- Hard freeze (28°F) ends
- Apr 21
Frost likely Fri night, low 29°F
National Weather Service forecast, updated Oct 22, 12:57 UTC
- ThuOct 2235°possible frost
- FriOct 2329°frost
- SatOct 2430°frost
- SunOct 2535°possible frost
- MonOct 2642°
- TueOct 2736°possible frost
- WedOct 2838°
Planting calendar for Marlborough
Windows count forward or back from the average frost dates above. Click a crop for dates across Massachusetts.
TomatoesMay 9–May 23
PumpkinsMay 16–May 30
SunflowersMay 2–May 23
CucumbersMay 16–May 23
CornMay 9–May 23
Sweet potatoesMay 23–Jun 6
WatermelonMay 16–May 30
Green beansMay 9–May 30
ZucchiniMay 9–May 23
OkraMay 23–Jun 6
PeppersMay 16–May 30
BasilMay 9–May 23
Butternut squashMay 9–May 23
CantaloupeMay 16–May 30
EggplantMay 16–May 30
PotatoesApr 4–Apr 18
OnionsMar 21–Apr 11
CarrotsApr 11–May 16
LettuceApr 18–May 9
BroccoliApr 4–Apr 18
BeetsApr 4–May 16
PeasMar 21–Apr 4
CabbageApr 4–Apr 18
RadishesMar 28–May 9
Brussels sproutsApr 18–May 2
SpinachMar 21–Apr 11
CilantroApr 18–May 9
KaleApr 4–Apr 18
Collard greensApr 4–Apr 18
TurnipsApr 4–Apr 18
DillMay 2–May 16
CeleryMay 9–May 16
CauliflowerApr 18–May 2
LeeksApr 18–May 2
Swiss chardApr 18–May 16
ParsleyApr 18–May 9
Tulip bulbsSep 22–Oct 27
GarlicSep 15–Oct 20
Daffodil bulbsSep 8–Oct 20
StrawberriesApr 4–Apr 18
AsparagusApr 4–Apr 18Frost probabilities
| Threshold | Spring, 90% chance later | Spring, 50% | Spring, 10% | Fall, 10% chance earlier | Fall, 50% | Fall, 90% |
|---|---|---|---|---|---|---|
| Light frost, 32°F | Apr 22 | May 2 | May 16 | Sep 25 | Oct 6 | Oct 22 |
| Hard freeze, 28°F | Apr 8 | Apr 21 | May 5 | Oct 2 | Oct 18 | Nov 3 |
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 Maynard 2 (USC00194580) sits 7.7 miles from the center of Marlborough at 205 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 Marlborough, MA?
The average last frost date in Marlborough is May 2, based on NOAA 1991–2020 climate normals. There is a 10% chance of frost after May 16.
When is the first frost in Marlborough?
The first frost in fall usually comes around October 6. One year in ten it arrives before September 25.
How long is the growing season in Marlborough?
About 156 days between the average last and first frost.
When should I plant tomatoes in Marlborough?
Plant tomato seedlings outside from May 9 to May 23. Start seeds indoors six to eight weeks earlier.
Nearby in Massachusetts
- FraminghamApr 26
- MilfordApr 30
- WellesleyApr 26
- WorcesterApr 23
- WalthamApr 28
- NeedhamApr 26
- LeominsterApr 29
- NewtonApr 19
- LexingtonApr 28
- WatertownApr 19
- BelmontApr 19
- Franklin TownApr 30