Last frost date in Arlington, MA
The average last frost in Arlington is April 28. By May 12 the chance of another 32°F night drops to 1 in 10. The first fall frost usually arrives about October 10, which leaves 165 frost-free days. An early freeze before September 28 happens one year in ten.
- Safe after (10% risk)
- May 12
- Average first frost
- Oct 10
- Frost-free season
- 165 days
- Hard freeze (28°F) ends
- Apr 12
Frost likely Fri night, low 31°F
National Weather Service forecast, updated Oct 22, 12:57 UTC
- ThuOct 2238°
- FriOct 2331°frost
- SatOct 2432°frost
- SunOct 2538°
- MonOct 2644°
- TueOct 2739°
- WedOct 2841°
Planting calendar for Arlington
Windows count forward or back from the average frost dates above. Click a crop for dates across Massachusetts.
Frost probabilities
| Threshold | Spring, 90% chance later | Spring, 50% | Spring, 10% | Fall, 10% chance earlier | Fall, 50% | Fall, 90% |
|---|---|---|---|---|---|---|
| Light frost, 32°F | Apr 13 | Apr 28 | May 12 | Sep 28 | Oct 10 | Oct 28 |
| Hard freeze, 28°F | Apr 1 | Apr 12 | Apr 29 | Oct 7 | Oct 25 | Nov 8 |
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 Bedford Hanscom Field (USW00014702) sits 7.3 miles from the center of Arlington at 133 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 Arlington, MA?
The average last frost date in Arlington is April 28, based on NOAA 1991–2020 climate normals. There is a 10% chance of frost after May 12.
When is the first frost in Arlington?
The first frost in fall usually comes around October 10. One year in ten it arrives before September 28.
How long is the growing season in Arlington?
About 165 days between the average last and first frost.
When should I plant tomatoes in Arlington?
Plant tomato seedlings outside from May 5 to May 19. Start seeds indoors six to eight weeks earlier.