Lynn, Massachusetts: planting zone & frost dates
Lynn is in USDA plant hardiness zone 7a, where the average coldest winter night reaches 0 to 5°F (-17.8 to -15.0°C). The typical last spring frost is around May 1 and the first fall frost around Oct 14.
Frost dates
| Probability | Last spring frost (32°F) | First fall frost (32°F) |
|---|---|---|
| Safer (10% risk) | May 13 | Oct 5 |
| Typical planning date (30% risk) | May 1 | Oct 14 |
| Median (50%) | Apr 25 | Oct 20 |
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 MARBLEHEAD, MA (USC00194502), 5.3 mi (8.5 km) from the city center and 56 ft lower than the city center (-17 m). Record used for the 1991–2020 normals: 26 years.
Why your yard may differ from the station: microclimates.
Hardiness zone across Lynn
Lynn spans more than one half-zone. Share of the city's land area by zone (via its 5 ZIP codes): 7a (53%), 6b (47%). The headline zone is the one covering the most land. Look up your ZIP for your exact zone.
Vegetable planting calendar for Lynn
Dates are counted from the 30%-risk frost dates above (last frost May 1, first frost Oct 14). Shift a week later in cold spots or low-lying ground.
| Crop | Start indoors | Transplant / plant out | Direct sow | Fall crop sow/plant |
|---|---|---|---|---|
| Tomato | Mar 6 – Mar 20 | May 8 – May 22 | — | — |
| Pepper | Feb 20 – Mar 6 | May 15 – May 29 | — | — |
| Lettuce | Mar 20 – Apr 3 | Apr 17 – May 8 | Apr 3 – May 15 | Aug 5 – Sep 2 |
| Green Beans | — | — | May 8 – Jun 12 | Jul 22 – Aug 5 |
| Sweet Corn | — | — | May 8 – Jun 5 | — |
| Zucchini & Summer Squash | Apr 3 – Apr 10 | May 8 – May 22 | May 8 – May 29 | Jul 22 – Aug 5 |
| Cucumber | Apr 3 – Apr 10 | May 15 – May 22 | May 8 – May 29 | Jul 22 – Aug 5 |
| Carrot | — | — | Apr 10 – May 15 | Jul 22 – Aug 5 |
| Onion | Feb 6 – Feb 20 | Apr 3 – Apr 17 | — | — |
| Potato | — | Apr 3 – Apr 24 | — | — |
| Basil | Mar 20 – Apr 3 | May 15 – May 29 | May 15 – Jun 5 | — |
| Spinach | — | — | Mar 20 – Apr 17 | Aug 19 – Sep 16 |
| Kale | Mar 6 – Mar 20 | Apr 3 – Apr 24 | Apr 3 – Apr 24 | Aug 5 – Sep 2 |
| Broccoli | Mar 6 – Mar 20 | Apr 17 – May 8 | — | Jul 22 – Aug 5 |
| Peas | — | — | Mar 20 – Apr 10 | Aug 5 – Aug 19 |
| Eggplant | Feb 20 – Mar 6 | May 15 – May 29 | — | — |
| Cabbage | Mar 6 – Mar 20 | Apr 3 – Apr 17 | — | Jul 22 – Aug 5 |
| Radish | — | — | Mar 27 – May 15 | Sep 2 – Sep 30 |
| Strawberry | — | Apr 3 – Apr 24 | — | — |
| Beets | — | — | Apr 10 – May 22 | Aug 5 – Aug 19 |
Nearby cities in Massachusetts
- Boston — zone 6b, last frost Apr 8, first frost Nov 3
- Somerville — zone 7a, last frost Apr 8, first frost Nov 3
- Cambridge — zone 6b, last frost Apr 8, first frost Nov 3
- Quincy — zone 6b, last frost Apr 30, first frost Oct 15
- Newton — zone 6b, last frost Apr 24, first frost Oct 16
- Lawrence — zone 6b, last frost Apr 19, first frost Oct 22
More: all Massachusetts cities · other zone 7a cities: Louisville, KY, Wichita, KS, Cleveland, OH, Lexington, KY, St. Louis, MO, Boise, ID, Amarillo, TX, Providence, RI
Lynn gardening questions
When is the last frost in Lynn, MA?
Plan around May 1. At NOAA's Marblehead, MA station, 5.3 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 25, and after May 13 the risk drops to about 1 in 10. A hard freeze (28°F) usually ends earlier, around Apr 11. The 90% and 10% dates are 31 days apart, close to the 36-day median for cities on this site.
When should I plant tomatoes in Lynn, MA?
Start seeds indoors Mar 6 – Mar 20 and set transplants outside May 8 – May 22, once nights stay above 50°F and the soil is near 60°F. That leaves 166 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 Lynn?
About 176 days without a 32°F frost in a typical (median) year. In 9 years out of 10 the season lasts at least 157 days, and in 1 year in 10 it runs 195 days or more. In fall there is a 10% chance of frost by Oct 5 and a 30% chance by Oct 14. That ranks 8th longest of 13 Massachusetts cities on this site.
When should I plant a fall garden in Lynn?
Count back from the first fall frost (Oct 14): transplant broccoli Jul 22 – Aug 5; sow kale Aug 5 – Sep 2; sow lettuce Aug 5 – Sep 2; sow radishes Sep 2 – Sep 30. Hardy crops keep growing through light frosts; the median 28°F hard freeze here is Oct 31. How the math works: succession and fall planting.
Did Lynn's hardiness zone change on the 2023 map?
Yes. Most of Lynn was zone 6b on the 2012 map and is zone 7a on the 2023 map — half a zone warmer, like about 56% of U.S. ZIP codes. The shift comes from a newer 1991–2020 averaging period plus more weather stations and better mapping; it does not mean last frost comes earlier. Why the 2023 map is warmer.
Is all of Lynn in zone 7a?
No. Zone 7a covers about 53% of the city's land; the rest is in 6b (47%), measured across the city's 5 ZIP codes. Check your own ZIP code in the table above or with the ZIP lookup.