In Boston, MA, the average last spring frost is Apr 4 and the average first fall frost is Nov 9, which leaves about 218 frost-free days for the garden. These dates come from NOAA climate normals for the Boston Logan International Airport, MA weather station, at 12 feet above sea level.
A long season lets you do more than one planting: a spring crop, a second planting of quick crops in summer, and a fall garden. Succession planting works well here. Frost timing varies from year to year: in about 1 spring in 10 the last frost falls as late as Apr 17, and in about 1 fall in 10 the first frost arrives as early as Oct 29.
Frost dates for Boston, MA
| Chance of a freeze (32°F) after or before this date | Last spring frost | First fall frost | Freeze-free season |
|---|---|---|---|
| Optimistic (about 1 year in 10) | Mar 25 | Nov 22 | 242 days |
| Average (half of years) | Apr 4 | Nov 9 | 218 days |
| Cautious (9 years in 10 are safe) | Apr 17 | Oct 29 | 195 days |
Source: NOAA NCEI U.S. Climate Normals, 1991 to 2020. Use the cautious dates for tender crops such as tomatoes and peppers.
When to plant in Boston, MA
These windows count weeks forward and back from the average frost dates above. They are planning guides: check the forecast before planting tender crops, and see our what to plant now tool for today's date.
| Crop | Start seeds indoors | Plant outdoors in spring | Plant in fall |
|---|---|---|---|
| Tomatoes | Feb 7 to Feb 21 | Apr 11 to Apr 18 | – |
| Peppers | Jan 24 to Feb 7 | Apr 18 to Apr 25 | – |
| Eggplant | Jan 24 to Feb 7 | Apr 18 to Apr 25 | – |
| Onions | Jan 24 to Feb 7 | Mar 7 to Mar 21 | – |
| Parsley | Jan 24 to Feb 7 | Apr 4 to Apr 11 | – |
| Broccoli, cabbage, cauliflower | Feb 7 to Feb 21 | Mar 21 to Mar 28 | Aug 17 to Sep 14 |
| Basil | Feb 21 to Feb 21 | Apr 11 to Apr 18 | – |
| Peas | Sow outdoors | Feb 21 to Mar 7 | Aug 17 to Sep 14 |
| Spinach | Sow outdoors | Feb 21 to Mar 7 | Sep 14 to Oct 12 |
| Radishes | Sow outdoors | Feb 21 to Mar 7 | Sep 14 to Oct 12 |
| Lettuce | Sow outdoors | Mar 7 to Mar 21 | Sep 14 to Oct 12 |
| Carrots | Sow outdoors | Mar 7 to Mar 21 | Aug 17 to Sep 14 |
| Beets | Sow outdoors | Mar 7 to Mar 21 | Aug 17 to Sep 14 |
| Potatoes | Sow outdoors | Mar 7 to Mar 21 | – |
| Kale | Sow outdoors | Mar 7 to Mar 21 | Aug 17 to Sep 14 |
| Swiss chard | Sow outdoors | Mar 21 to Apr 4 | – |
| Cilantro | Sow outdoors | Mar 21 to Apr 4 | Sep 14 to Oct 12 |
| Dill | Sow outdoors | Apr 4 to Apr 11 | – |
| Bush beans | Sow outdoors | Apr 11 to Apr 18 | Aug 6 to Aug 20 |
| Pole beans | Sow outdoors | Apr 11 to Apr 18 | – |
| Sweet corn | Sow outdoors | Apr 11 to Apr 18 | – |
| Cucumbers | Sow outdoors | Apr 11 to Apr 18 | Jul 27 to Aug 10 |
| Zucchini and summer squash | Sow outdoors | Apr 11 to Apr 18 | Aug 6 to Aug 20 |
| Winter squash | Sow outdoors | Apr 11 to Apr 18 | – |
| Sweet potatoes (slips) | Sow outdoors | Apr 18 to May 2 | – |
| Okra | Sow outdoors | Apr 18 to May 2 | – |
A dash in the fall column means the crop is not usually planted in fall, or the season is too short.
Overnight lows this week
No frost is forecast in the next week, according to the National Weather Service.
| Night | Forecast low | Frost risk |
|---|---|---|
| Sun 15 night | 37°F | No frost expected |
| Mon 16 night | 37°F | No frost expected |
| Tue 17 night | 42°F | No frost expected |
| Wed 18 night | 45°F | No frost expected |
| Thu 19 night | 47°F | No frost expected |
| Fri 20 night | 46°F | No frost expected |
| Sat 21 night | 49°F | No frost expected |
Live forecast for the station location, from the National Weather Service. For your own ZIP code, use our garden weather forecast.
More garden tools for Boston, MA
- Frost dates by ZIP code for your exact location
- What to plant now, based on today's date
- Garden weather forecast by ZIP code
- Safe transplant date calculator
Frequently asked questions
When is the last frost in Boston, MA?
The average last spring frost is Apr 4. A late frost as far out as Apr 17 happens in about 1 year in 10, so tender plants such as tomatoes and peppers are safest after that cautious date.
When is the first frost in Boston, MA?
The average first fall frost is Nov 9. It can arrive as early as Oct 29 in about 1 year in 10, so plan to harvest tender crops before then.
How long is the growing season in Boston, MA?
The average freeze-free season is about 218 days, between the average last spring frost and the average first fall frost.
Where do these dates come from?
They come from the NOAA 1991 to 2020 U.S. Climate Normals for the Boston Logan International Airport, MA station. Hills, valleys, lakes and city heat can shift frost by a week or more, so compare with neighbors who garden near you.