US Grow Zones

Lawrence, Massachusetts: planting zone & frost dates

Last updated · Sources: PRISM/OSU 2023 ZIP zone listings; NOAA NCEI 1991–2020 Climate Normals (station USC00194105); U.S. Census Bureau — see methodology

Lawrence 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 19 and the first fall frost around Oct 22.

Hardiness zone6B-5 to 0°F
Last spring frostApr 1930% chance of frost after
First fall frostOct 2230% chance of frost before
Growing season198 daysmedian frost-free days

Frost dates

ProbabilityLast spring frost (32°F)First fall frost (32°F)
Safer (10% risk)Apr 29Oct 13
Typical planning date (30% risk)Apr 19Oct 22
Median (50%)Apr 13Oct 28

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 LAWRENCE, MA (USC00194105), 0.2 mi (0.4 km) from the city center and 3 ft higher than the city center (+1 m). Record used for the 1991–2020 normals: 27 years.

Frost probability in spring and fall, Lawrence, MAChance of a 32°F frost in Lawrence, MA, NOAA 1991–2020. Spring: the chance of another frost falls from 90% on Apr 1 to 10% on Apr 29. Fall: the chance that the first frost has arrived rises from 10% on Oct 13 to 90% on Nov 10.0%50%100%Spring: later frostMar 15Apr 1Apr 15May 130%: Apr 19Fall: frost arrivedOct 15Nov 1Nov 15Dec 130%: Oct 2232°F frost28°F hard freezeplanning date
Shaded areas show the chance of a 32°F frost: falling through spring, rising through fall. The dashed line is the 28°F hard-freeze curve. Data: NOAA 1991–2020 Normals, station USC00194105.
Frost-free growing season in Lawrence, MA1 in 10 risk: Apr 29 to Oct 13 (167 days); 3 in 10 risk: Apr 19 to Oct 22 (186 days); Median (50%): Apr 13 to Oct 28 (198 days); No 28°F freeze: Apr 3 to Nov 9 (220 days). In 9 of 10 years the 32°F-free season is at least 176 days.Frost-free days, spring to fallJFMAMJJASOND1 in 10 risk167 days3 in 10 risk186 daysMedian (50%)198 daysNo 28°F freeze220 days
Frost-free window at three risk levels, plus the window between 28°F hard freezes. Read about what the probabilities mean.

Why your yard may differ from the station: microclimates.

Hardiness zone across Lawrence

All 3 ZIP codes covering Lawrence are in zone 6b.

ZIP codes in Lawrence and their zones
ZIPZoneShare of city land
018436b48.7%
018416b43.9%
018406b7.4%

Vegetable planting calendar for Lawrence

Dates are counted from the 30%-risk frost dates above (last frost Apr 19, first frost Oct 22). Shift a week later in cold spots or low-lying ground.

CropStart indoorsTransplant / plant outDirect sowFall crop sow/plant
TomatoFeb 22 – Mar 8Apr 26 – May 10——
PepperFeb 8 – Feb 22May 3 – May 17——
LettuceMar 8 – Mar 22Apr 5 – Apr 26Mar 22 – May 3Aug 13 – Sep 10
Green Beans——Apr 26 – May 31Jul 30 – Aug 13
Sweet Corn——Apr 26 – May 24—
Zucchini & Summer SquashMar 22 – Mar 29Apr 26 – May 10Apr 26 – May 17Jul 30 – Aug 13
CucumberMar 22 – Mar 29May 3 – May 10Apr 26 – May 17Jul 30 – Aug 13
Carrot——Mar 29 – May 3Jul 30 – Aug 13
OnionJan 25 – Feb 8Mar 22 – Apr 5——
Potato—Mar 22 – Apr 12——
BasilMar 8 – Mar 22May 3 – May 17May 3 – May 24—
Spinach——Mar 8 – Apr 5Aug 27 – Sep 24
KaleFeb 22 – Mar 8Mar 22 – Apr 12Mar 22 – Apr 12Aug 13 – Sep 10
BroccoliFeb 22 – Mar 8Apr 5 – Apr 26—Jul 30 – Aug 13
Peas——Mar 8 – Mar 29Aug 13 – Aug 27
EggplantFeb 8 – Feb 22May 3 – May 17——
CabbageFeb 22 – Mar 8Mar 22 – Apr 5—Jul 30 – Aug 13
Radish——Mar 15 – May 3Sep 10 – Oct 8
Strawberry—Mar 22 – Apr 12——
Beets——Mar 29 – May 10Aug 13 – Aug 27

Nearby cities in Massachusetts

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

Lawrence gardening questions

When is the last frost in Lawrence, MA?

Plan around Apr 19. At NOAA's Lawrence, MA station, 0.2 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 13, and after Apr 29 the risk drops to about 1 in 10. A hard freeze (28°F) usually ends earlier, around Apr 3. The last frost is fairly predictable here: only 28 days separate the 90% and 10% dates (median for cities on this site: 36 days).

When should I plant tomatoes in Lawrence, MA?

Start seeds indoors Feb 22 – Mar 8 and set transplants outside Apr 26 – May 10, once nights stay above 50°F and the soil is near 60°F. That leaves 186 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 Lawrence?

About 198 days without a 32°F frost in a typical (median) year. In 9 years out of 10 the season lasts at least 176 days, and in 1 year in 10 it runs 218 days or more. In fall there is a 10% chance of frost by Oct 13 and a 30% chance by Oct 22. That ranks 4th longest of 13 Massachusetts cities on this site.

When should I plant a fall garden in Lawrence?

Count back from the first fall frost (Oct 22): transplant broccoli Jul 30 – Aug 13; sow kale Aug 13 – Sep 10; sow lettuce Aug 13 – Sep 10; sow radishes Sep 10 – Oct 8. Hardy crops keep growing through light frosts; the median 28°F hard freeze here is Nov 9. How the math works: succession and fall planting.

Did Lawrence's hardiness zone change on the 2023 map?

Yes. Most of Lawrence was zone 6a on the 2012 map and is zone 6b 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.

How does Lawrence compare with Lowell, MA?

Both are in zone 6b. The typical last spring frost in Lawrence (Apr 19) comes about 14 days earlier than in Lowell, MA (May 3), 9 miles away, and the first fall frost is Oct 22 versus Oct 5. The two cities use different NOAA stations.