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Frost dates for Westport Island, ME

NOAA weather station USC00179547 at 90 ft elevation. Based on 11 years within 1991-2020. Last verified 2026-10-17.

Last spring freeze (32°F)

Apr 28

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

May 2 30% risk · May 9 10% risk

First fall freeze (32°F)

Oct 21

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

Oct 5 10% chance of a freeze earlier than this

Freeze-free season

175 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 23 / May 15 / May 10Sep 25 / Oct 7
32°F (freeze)May 9 / May 2 / Apr 28Oct 5 / Oct 21
28°F (hard freeze)Apr 26 / Apr 19 / Apr 13Oct 22 / Nov 4

Also at 32°F, last-freeze 70% date Apr 24 and 90% date Apr 16 (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 USC00179547, 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.

UMaine Extension gives central-Maine planting dates and says to plant 10-14 days earlier on the coast and 10-14 days later in northern Maine (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
SpinachFeb 7 – Mar 14Set out Mar 21 – Apr 11Start 4-6 wk before set-out; set out 3-6 wk before last frost.
BroccoliFeb 21 – Mar 21Set out Apr 4 – Apr 18Start 4-6 wk before set-out; set out 2-4 wk before last frost.
Brussels sproutFeb 21 – Mar 21Set out Apr 4 – Apr 18Start 4-6 wk before set-out; set out 2-4 wk before last frost.
CabbageFeb 21 – Mar 7Set out Apr 4Start 4-6 wk before set-out; set out 4 wk before last frost.
KaleFeb 21 – Mar 7Set out Apr 4Start 4-6 wk before set-out; set out 4 wk before last frost.
KohlrabiFeb 21 – Mar 7Set out Apr 4Start 4-6 wk before set-out; set out 4 wk before last frost.
LeekJan 24 – Feb 7Set out Apr 4Start 8-10 wk before set-out; set out 4 wk before last frost.
LettuceFeb 28 – Mar 14Set out Apr 4 – Apr 11Start 4-5 wk before set-out; set out 3-4 wk before last frost.
OnionJan 24 – Feb 7Set out Apr 4Start 8-10 wk before set-out; set out 4 wk before last frost.
Radish—Sow Apr 4 – Apr 18Sow seed in garden 2-4 wk before last frost.
Turnip—Sow Apr 4 – Apr 18Sow seed in garden 2-4 wk before last frost.
ParsleyJan 31 – Feb 14Set out Apr 11 – Apr 18Start 9-10 wk before set-out; set out 2-3 wk before last frost.
CauliflowerMar 7 – Mar 21Set out Apr 18Start 4-6 wk before set-out; set out 2 wk before last frost.
Potato—Sow Apr 18 – Apr 25Plant seed potatoes 1-2 wk before last frost.
Swiss chardMar 7 – Mar 21Set out Apr 18; or sow Apr 4Start 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 May 2Sow seed in garden after last frost.
CeleryFeb 7 – Feb 21Set out on/after May 2Start 10-12 wk before set-out; set out after last frost.
Parsnip—Sow on/after May 2Sow seed in garden after last frost.
CucumberApr 11 – Apr 25Set out May 9 – May 16
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 May 9 – May 16Plant slips (young plants) 1-2 wk after last frost.
TomatoMar 14 – Apr 4Set out May 9 – May 16Start 6-8 wk before set-out; set out 1-2 wk after last frost.
BasilMar 21 – Apr 4Set out May 16Start 6-8 wk before set-out; set out 2 wk after last frost.
EggplantMar 7 – Mar 28Set out May 16 – May 23Start 8-10 wk before set-out; set out 2-3 wk after last frost.
MelonApr 18 – Apr 25Set out May 16Start 3-4 wk before set-out; set out 2 wk after last frost.
PepperMar 7 – Mar 21Set out May 16Start 8-10 wk before set-out; set out 2 wk after last frost.
PumpkinApr 18 – Apr 25Set out May 16
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 18 – Apr 25Set out May 16
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 18 – Apr 25Set out May 16
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 18 – Apr 25Set out May 16
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 Oct 21; there is a 10% chance of one before Oct 5. 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 7 and 10% date Sep 25. UNH Extension notes many fall vegetables tolerate mild frosts down to about 28°F (median first 28°F here: Nov 4), 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 90 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