New England Garden Calendar

Home / Massachusetts / Chatham Muni AP

Frost dates for Chatham Muni AP, MA

NOAA weather station USW00094624 at 68 ft elevation. Based on 21 years within 1991-2020. Last verified 2026-10-17.

Last spring freeze (32°F)

Apr 13

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

Apr 18 30% risk · Apr 26 10% risk

First fall freeze (32°F)

Nov 4

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

Oct 21 10% chance of a freeze earlier than this

Freeze-free season

206 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 8 / May 1 / Apr 27Oct 10 / Oct 23
32°F (freeze)Apr 26 / Apr 18 / Apr 13Oct 21 / Nov 4
28°F (hard freeze)Apr 11 / Apr 4 / Mar 31Nov 3 / Nov 19

Also at 32°F, last-freeze 70% date Apr 8 and 90% date Apr 1 (frost still likely after these early dates). Data quality: Representative: 10+ years of qualifying data, missing months filled from nearby stations. Source: NOAA NCEI U.S. Climate Normals 1991-2020, station USW00094624, 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 24 – Feb 28Set out Mar 7 – Mar 28Start 4-6 wk before set-out; set out 3-6 wk before last frost.
BroccoliFeb 7 – Mar 7Set out Mar 21 – Apr 4Start 4-6 wk before set-out; set out 2-4 wk before last frost.
Brussels sproutFeb 7 – Mar 7Set out Mar 21 – Apr 4Start 4-6 wk before set-out; set out 2-4 wk before last frost.
CabbageFeb 7 – Feb 21Set out Mar 21Start 4-6 wk before set-out; set out 4 wk before last frost.
KaleFeb 7 – Feb 21Set out Mar 21Start 4-6 wk before set-out; set out 4 wk before last frost.
KohlrabiFeb 7 – Feb 21Set out Mar 21Start 4-6 wk before set-out; set out 4 wk before last frost.
LeekJan 10 – Jan 24Set out Mar 21Start 8-10 wk before set-out; set out 4 wk before last frost.
LettuceFeb 14 – Feb 28Set out Mar 21 – Mar 28Start 4-5 wk before set-out; set out 3-4 wk before last frost.
OnionJan 10 – Jan 24Set out Mar 21Start 8-10 wk before set-out; set out 4 wk before last frost.
Radish—Sow Mar 21 – Apr 4Sow seed in garden 2-4 wk before last frost.
Turnip—Sow Mar 21 – Apr 4Sow seed in garden 2-4 wk before last frost.
ParsleyJan 17 – Jan 31Set out Mar 28 – Apr 4Start 9-10 wk before set-out; set out 2-3 wk before last frost.
CauliflowerFeb 21 – Mar 7Set out Apr 4Start 4-6 wk before set-out; set out 2 wk before last frost.
Potato—Sow Apr 4 – Apr 11Plant seed potatoes 1-2 wk before last frost.
Swiss chardFeb 21 – Mar 7Set out Apr 4; or sow Mar 21Start 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 18Sow seed in garden after last frost.
CeleryJan 24 – Feb 7Set out on/after Apr 18Start 10-12 wk before set-out; set out after last frost.
Parsnip—Sow on/after Apr 18Sow seed in garden after last frost.
CucumberMar 28 – Apr 11Set out Apr 25 – May 2
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 25 – May 2Plant slips (young plants) 1-2 wk after last frost.
TomatoFeb 28 – Mar 21Set out Apr 25 – May 2Start 6-8 wk before set-out; set out 1-2 wk after last frost.
BasilMar 7 – Mar 21Set out May 2Start 6-8 wk before set-out; set out 2 wk after last frost.
EggplantFeb 21 – Mar 14Set out May 2 – May 9Start 8-10 wk before set-out; set out 2-3 wk after last frost.
MelonApr 4 – Apr 11Set out May 2Start 3-4 wk before set-out; set out 2 wk after last frost.
PepperFeb 21 – Mar 7Set out May 2Start 8-10 wk before set-out; set out 2 wk after last frost.
PumpkinApr 4 – Apr 11Set out May 2
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 squashApr 4 – Apr 11Set out May 2
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 squashApr 4 – Apr 11Set out May 2
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.
ZucchiniApr 4 – Apr 11Set out May 2
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 4; there is a 10% chance of one before Oct 21. 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 23 and 10% date Oct 10. UNH Extension notes many fall vegetables tolerate mild frosts down to about 28°F (median first 28°F here: Nov 19), 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 68 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.

Nearby stations