Frost dates · USDA zone 6b

Frost dates for Cambridge, MA

Cambridge, MA sees its last 32 °F night of spring around April 19 and its first of fall around October 23 — a 185-day freeze-free season in a typical year.

Apr 19Last spring frostmedian · 1 in 10 years after May 3
Oct 23First fall frostmedian · 1 in 10 years before Oct 8
185Freeze-free daysmedian year · ≥165 in 9 of 10
6bUSDA zone2023 map · ZIP 02163
Build a Cambridge sauce plan →

Pick a sauce; the Plan Builder runs this station's dates and hands back the calendar, plant count and gear list.

Freeze odds, by date

OddsLast spring freeze afterFirst fall freeze before
9 years in 10Apr 6Nov 5
Median — 1 year in 2Apr 19Oct 23
1 year in 10May 3Oct 8

The top row is the risky edge: in 9 years of 10 a spring freeze still comes after it, so tender transplants set out then need cover. The bottom row is the cautious date — only 1 year in 10 freezes after it — and the one to plan uncovered tender transplants against. Freeze-free season: 185 days median, at least 165 in 9 years of 10, at least 204 days in 1 year of 10. NOAA ranks season length year by year, so it is not the gap between two rows above. A hard freeze (28 °F) has a median last date of Apr 5 and first of Nov 3.

Cambridge planting calendar, 2027

Every row runs from the median last frost (Apr 19) and median first frost (Oct 23) above, using each cultivar's days to maturity. Same engine as the Plan Builder.

CropStart indoorsTransplant / plantFirst harvestDays
Hardneck GarlicSiberian (porcelain hardneck)—Oct 15prior fallJun 12240 from sow
Spanish OnionYellow Sweet Spanish (long-day)Jan 25Mar 22Jul 10110 from transplant
Mustard greensGarnet Giant (Brassica juncea)Direct sowApr 19May 1930 from sow
CilantroSlow Bolt (Coriandrum sativum)Apr 5Apr 5May 2045 from sow
Genovese BasilGenoveseMar 22May 3Jul 260 from transplant
CayenneLong Slim Cayenne (Capsicum annuum)Feb 22Apr 26Jul 1075 from transplant
HabaneroOrange Habanero (Capsicum chinense)Feb 8May 3Aug 695 from transplant
JalapeñoEarly Jalapeño (Capsicum annuum)Feb 22Apr 26Jul 1075 from transplant
Marconi Red PepperMarconi Red (Capsicum annuum)Feb 22Apr 26Jul 1580 from transplant
SerranoSerrano Tampiqueño (Capsicum annuum)Feb 22Apr 26Jul 1580 from transplant
Nantes CarrotScarlet NantesApr 5Apr 5Jun 1470 from sow
TomatilloToma VerdeMar 8Apr 26Jul 570 from transplant
Roma TomatoRoma VF (determinate paste)Mar 8Apr 26Jul 1075 from transplant
San Marzano TomatoSan Marzano (indeterminate paste)Mar 8Apr 26Jul 1580 from transplant

Tight means first harvest lands within two weeks of the median first fall frost: start that crop indoors on time or cover it in fall.

Cambridge frost questions

When is the last frost in Cambridge, MA?

The median last 32 °F freeze at JAMAICA PLAIN, MA is April 19: half of years see a later one. One year in ten, a freeze still comes after May 3; nine years in ten, it comes after April 6. Source: NOAA NCEI 1991–2020 U.S. Climate Normals.

When is the first frost in Cambridge, MA?

The median first 32 °F freeze of fall is October 23. One year in ten it arrives before October 8; nine years in ten, before November 5.

How long is the growing season in Cambridge, MA?

185 days between the last spring and first fall 32 °F freeze in a median year. Nine years in ten the season runs at least 165 days; one year in ten, at least 204 days.

What growing zone is Cambridge, MA?

USDA hardiness zone 6b, per the 2023 USDA Plant Hardiness Zone Map for ZIP 02163. A zone describes the coldest winter night, not when frost ends, so it is the wrong number for a planting calendar — the frost dates on this page are the right one.

When should I plant tomatoes in Cambridge, MA?

Start Roma VF (determinate paste) seeds indoors around Mar 8 and transplant around Apr 26, 1 week after the median last frost. To cut the freeze risk to one year in ten, wait for May 3. First ripe fruit lands around Jul 10.

When should I plant peppers in Cambridge, MA?

Sow jalapeño indoors on a heat mat around Feb 22; transplant no earlier than Apr 26, and wait past it until nights hold above 50 °F — that can run weeks later. First green pods around Jul 10.

Nearby in Massachusetts

All Massachusetts frost dates → · How frost-date math drives a sowing calendar →