Newton, Massachusetts: planting zone & frost dates
Newton is in USDA plant hardiness zone 6b, where the average coldest winter night reaches -5 to 0°F (-20.6 to -17.8°C). The typical last spring frost is around Apr 24 and the first fall frost around Oct 16.
Frost dates
| Probability | Last spring frost (32°F) | First fall frost (32°F) |
|---|---|---|
| Safer (10% risk) | May 3 | Oct 8 |
| Typical planning date (30% risk) | Apr 24 | Oct 16 |
| Median (50%) | Apr 19 | Oct 23 |
How to read this: after the spring "10% risk" date, a 32°F frost happens in only about 1 year in 10. In fall, the "10% risk" date is the early end — a frost before it happens about 1 year in 10.
Frost data comes from NOAA station JAMAICA PLAIN, MA (USC00193890), 4.7 mi (7.6 km) from the city center and 16 ft lower than the city center (-5 m). Record used for the 1991–2020 normals: 25 years.
Why your yard may differ from the station: microclimates.
Hardiness zone across Newton
All 10 ZIP codes covering Newton are in zone 6b.
Vegetable planting calendar for Newton
Dates are counted from the 30%-risk frost dates above (last frost Apr 24, first frost Oct 16). Shift a week later in cold spots or low-lying ground.
| Crop | Start indoors | Transplant / plant out | Direct sow | Fall crop sow/plant |
|---|---|---|---|---|
| Tomato | Feb 27 – Mar 13 | May 1 – May 15 | — | — |
| Pepper | Feb 13 – Feb 27 | May 8 – May 22 | — | — |
| Lettuce | Mar 13 – Mar 27 | Apr 10 – May 1 | Mar 27 – May 8 | Aug 7 – Sep 4 |
| Green Beans | — | — | May 1 – Jun 5 | Jul 24 – Aug 7 |
| Sweet Corn | — | — | May 1 – May 29 | — |
| Zucchini & Summer Squash | Mar 27 – Apr 3 | May 1 – May 15 | May 1 – May 22 | Jul 24 – Aug 7 |
| Cucumber | Mar 27 – Apr 3 | May 8 – May 15 | May 1 – May 22 | Jul 24 – Aug 7 |
| Carrot | — | — | Apr 3 – May 8 | Jul 24 – Aug 7 |
| Onion | Jan 30 – Feb 13 | Mar 27 – Apr 10 | — | — |
| Potato | — | Mar 27 – Apr 17 | — | — |
| Basil | Mar 13 – Mar 27 | May 8 – May 22 | May 8 – May 29 | — |
| Spinach | — | — | Mar 13 – Apr 10 | Aug 21 – Sep 18 |
| Kale | Feb 27 – Mar 13 | Mar 27 – Apr 17 | Mar 27 – Apr 17 | Aug 7 – Sep 4 |
| Broccoli | Feb 27 – Mar 13 | Apr 10 – May 1 | — | Jul 24 – Aug 7 |
| Peas | — | — | Mar 13 – Apr 3 | Aug 7 – Aug 21 |
| Eggplant | Feb 13 – Feb 27 | May 8 – May 22 | — | — |
| Cabbage | Feb 27 – Mar 13 | Mar 27 – Apr 10 | — | Jul 24 – Aug 7 |
| Radish | — | — | Mar 20 – May 8 | Sep 4 – Oct 2 |
| Strawberry | — | Mar 27 – Apr 17 | — | — |
| Beets | — | — | Apr 3 – May 15 | Aug 7 – Aug 21 |
Nearby cities in Massachusetts
- Cambridge — zone 6b, last frost Apr 8, first frost Nov 3
- Somerville — zone 7a, last frost Apr 8, first frost Nov 3
- Boston — zone 6b, last frost Apr 8, first frost Nov 3
- Quincy — zone 6b, last frost Apr 30, first frost Oct 15
- Lynn — zone 7a, last frost May 1, first frost Oct 14
- Brockton — zone 6b, last frost Apr 28, first frost Oct 13
More: all Massachusetts cities · other zone 6b cities: Columbus, OH, Indianapolis, IN, Boston, MA, Detroit, MI, Kansas City, MO, Cincinnati, OH, Pittsburgh, PA, Buffalo, NY
Newton gardening questions
When is the last frost in Newton, MA?
Plan around Apr 24. At NOAA's Jamaica Plain, MA station, 4.7 mi from the city center, there is a 30% chance of a 32°F frost after that date. Half of springs have their last frost by Apr 19, and after May 3 the risk drops to about 1 in 10. A hard freeze (28°F) usually ends earlier, around Apr 5. The last frost is fairly predictable here: only 27 days separate the 90% and 10% dates (median for cities on this site: 36 days).
When should I plant tomatoes in Newton, MA?
Start seeds indoors Feb 27 – Mar 13 and set transplants outside May 1 – May 15, once nights stay above 50°F and the soil is near 60°F. That leaves 175 days between the 30% frost dates, enough for most varieties including 80–85-day slicers. More: tomato planting dates by zone.
How long is the growing season in Newton?
About 185 days without a 32°F frost in a typical (median) year. In 9 years out of 10 the season lasts at least 165 days, and in 1 year in 10 it runs 204 days or more. In fall there is a 10% chance of frost by Oct 8 and a 30% chance by Oct 16. That ranks 5th longest of 13 Massachusetts cities on this site.
When should I plant a fall garden in Newton?
Count back from the first fall frost (Oct 16): transplant broccoli Jul 24 – Aug 7; sow kale Aug 7 – Sep 4; sow lettuce Aug 7 – Sep 4; sow radishes Sep 4 – Oct 2. Hardy crops keep growing through light frosts; the median 28°F hard freeze here is Nov 3. How the math works: succession and fall planting.
Did Newton's hardiness zone change on the 2023 map?
No. Going by the zone that covers most of the city's land, Newton is zone 6b on both the 2012 and the 2023 USDA maps (PRISM/OSU ZIP listings). About 42% of U.S. ZIP codes kept their half-zone in 2023. Why the 2023 map is warmer.
How does Newton compare with Cambridge, MA?
Both are in zone 6b. The typical last spring frost in Newton (Apr 24) comes about 16 days later than in Cambridge, MA (Apr 8), 6 miles away, and the first fall frost is Oct 16 versus Nov 3. The two cities use different NOAA stations.