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Frost dates for Boston Logan Intl AP, MA

NOAA weather station USW00014739 at 12 ft elevation. Based on 28 years within 1991-2020. Last verified 2026-10-17.

Last spring freeze (32°F)

Apr 4

median: freeze still happened after this date in half of years

Apr 8 30% risk · Apr 17 10% risk

First fall freeze (32°F)

Nov 9

median: a freeze had happened by this date in half of years

Oct 29 10% chance of a freeze earlier than this

Freeze-free season

218 days

median length between last spring and first fall 32°F freeze

How to read these dates

Spring: a "10% risk" date means NOAA's 1991-2020 data put the chance of a 32°F or colder night after that date at 10%. The "30% risk" date is the convention used by some popular frost calculators (the Old Farmer's Almanac says it uses a 30% probability threshold, source). Fall: a "10%" date means a 10% chance the first freeze comes before it. Source: NOAA readme.

Full table for this station

ThresholdSpring: latest-freeze date at risk of 10% / 30% / 50%Fall: first-freeze date at chance of 10% / 50%
36°F (frost possible)May 1 / Apr 22 / Apr 17Oct 15 / Oct 29
32°F (freeze)Apr 17 / Apr 8 / Apr 4Oct 29 / Nov 9
28°F (hard freeze)Apr 6 / Apr 1 / Mar 28Nov 8 / Nov 21

Also at 32°F, last-freeze 70% date Apr 1 and 90% date Mar 25 (frost still likely after these early dates). Data quality: Standard: 24+ years of qualifying data. Source: NOAA NCEI U.S. Climate Normals 1991-2020, station USW00014739, read 2026-10-17.

Is Memorial Day safe here?

Many New England gardeners wait for Memorial Day (it falls between May 25 and May 31). At this station, NOAA's chance of a 32°F or colder night after May 25 is under 10%, and after May 31 is under 10%. Your own spot may differ. See all stations.

UMass Extension says that in many areas of Massachusetts the last frost date is usually around May 15 (read 2026-10-17).

Your planting schedule

Pick how cautious you want to be. The dates apply UNH Extension's per-crop rules (UNH fact sheet, read 2026-10-17) to this station's last-freeze date. UNH's sheet does not say which probability its "last frost" means, so you choose. These are planning dates, not instructions; follow your seed packet and the weather.

Last-frost reference date

Showing the schedule for the 2027 season (dates repeat yearly). Table below defaults to Typical; it updates when you choose.

CropStart seeds indoorsOutdoorsUNH Extension rule used
SpinachJan 14 – Feb 18Set out Feb 25 – Mar 18Start 4-6 wk before set-out; set out 3-6 wk before last frost.
BroccoliJan 28 – Feb 25Set out Mar 11 – Mar 25Start 4-6 wk before set-out; set out 2-4 wk before last frost.
Brussels sproutJan 28 – Feb 25Set out Mar 11 – Mar 25Start 4-6 wk before set-out; set out 2-4 wk before last frost.
CabbageJan 28 – Feb 11Set out Mar 11Start 4-6 wk before set-out; set out 4 wk before last frost.
KaleJan 28 – Feb 11Set out Mar 11Start 4-6 wk before set-out; set out 4 wk before last frost.
KohlrabiJan 28 – Feb 11Set out Mar 11Start 4-6 wk before set-out; set out 4 wk before last frost.
LeekDec 31 – Jan 14Set out Mar 11Start 8-10 wk before set-out; set out 4 wk before last frost.
LettuceFeb 4 – Feb 18Set out Mar 11 – Mar 18Start 4-5 wk before set-out; set out 3-4 wk before last frost.
OnionDec 31 – Jan 14Set out Mar 11Start 8-10 wk before set-out; set out 4 wk before last frost.
Radish—Sow Mar 11 – Mar 25Sow seed in garden 2-4 wk before last frost.
Turnip—Sow Mar 11 – Mar 25Sow seed in garden 2-4 wk before last frost.
ParsleyJan 7 – Jan 21Set out Mar 18 – Mar 25Start 9-10 wk before set-out; set out 2-3 wk before last frost.
CauliflowerFeb 11 – Feb 25Set out Mar 25Start 4-6 wk before set-out; set out 2 wk before last frost.
Potato—Sow Mar 25 – Apr 1Plant seed potatoes 1-2 wk before last frost.
Swiss chardFeb 11 – Feb 25Set out Mar 25; or sow Mar 11Start 4-6 wk before set-out; set out 2 wk before last frost; or sow seed 4 wk before last frost.
Bean—Sow on/after Apr 8Sow seed in garden after last frost.
CeleryJan 14 – Jan 28Set out on/after Apr 8Start 10-12 wk before set-out; set out after last frost.
Parsnip—Sow on/after Apr 8Sow seed in garden after last frost.
CucumberMar 18 – Apr 1Set out Apr 15 – Apr 22
Direct sow when soil reaches 70°F		Start 3-4 wk before set-out; set out 1-2 wk after last frost; or sow when soil warms to 70°F.
Sweet potato—Plant slips Apr 15 – Apr 22Plant slips (young plants) 1-2 wk after last frost.
TomatoFeb 18 – Mar 11Set out Apr 15 – Apr 22Start 6-8 wk before set-out; set out 1-2 wk after last frost.
BasilFeb 25 – Mar 11Set out Apr 22Start 6-8 wk before set-out; set out 2 wk after last frost.
EggplantFeb 11 – Mar 4Set out Apr 22 – Apr 29Start 8-10 wk before set-out; set out 2-3 wk after last frost.
MelonMar 25 – Apr 1Set out Apr 22Start 3-4 wk before set-out; set out 2 wk after last frost.
PepperFeb 11 – Feb 25Set out Apr 22Start 8-10 wk before set-out; set out 2 wk after last frost.
PumpkinMar 25 – Apr 1Set out Apr 22
Direct sow when soil reaches 70°F		Start 3-4 wk before set-out; set out 2 wk after last frost; or sow when soil warms to 70°F.
Summer squashMar 25 – Apr 1Set out Apr 22
Direct sow when soil reaches 70°F		Start 3-4 wk before set-out; set out 2 wk after last frost; or sow when soil warms to 70°F.
Winter squashMar 25 – Apr 1Set out Apr 22
Direct sow when soil reaches 70°F		Start 3-4 wk before set-out; set out 2 wk after last frost; or sow when soil warms to 70°F.
ZucchiniMar 25 – Apr 1Set out Apr 22
Direct sow when soil reaches 70°F		Start 3-4 wk before set-out; set out 2 wk after last frost; or sow when soil warms to 70°F.
Rutabaga—Sow Jun 15 – Jul 15Sow seed in garden mid-June to mid-July (fixed dates, not tied to frost).
Beet—Sow when soil reaches 45°F (use a soil thermometer)Sow seed in garden when soil warms to 45°F.
Carrot—Sow when soil reaches 60°F (use a soil thermometer)Sow seed in garden when soil warms to 60°F.
Corn—Sow when soil reaches 60°F (use a soil thermometer)Sow seed in garden when soil warms to 60°F.
Pea—Sow as soon as soil thawsSow seed in garden as soon as soil thaws.

Fall: when the garden ends

At this station the median first 32°F freeze is Nov 9; there is a 10% chance of one before Oct 29. Tender crops (tomatoes, peppers, basil) can be damaged at 33-36°F (Almanac.com notes some plants are damaged in that range); the 36°F first-frost date here is median Oct 29 and 10% date Oct 15. UNH Extension notes many fall vegetables tolerate mild frosts down to about 28°F (median first 28°F here: Nov 21), and that row covers can extend the season. UNH: Fall vegetable gardening, read 2026-10-17.

Your garden is not the weather station

This station sits at 12 ft. UNH Extension says first-freeze dates vary "even between relatively close locations, based on factors such as elevation" (source), and notes that gardeners who keep garden journals can use their own records. Gardeners on Reddit describe the same thing: elevation and cold spots change when they can plant (for example r/vermont). Treat these dates as a starting point.

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