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Frost dates for W Thompson Lake, CT

NOAA weather station USC00069388 at 360 ft elevation. Based on 28 years within 1991-2020. Last verified 2026-10-17.

Last spring freeze (32°F)

May 1

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

May 7 30% risk · May 17 10% risk

First fall freeze (32°F)

Oct 9

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

Sep 30 10% chance of a freeze earlier than this

Freeze-free season

161 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 31 / May 20 / May 14Sep 20 / Oct 1
32°F (freeze)May 17 / May 7 / May 1Sep 30 / Oct 9
28°F (hard freeze)May 2 / Apr 25 / Apr 19Oct 6 / Oct 21

Also at 32°F, last-freeze 70% date Apr 27 and 90% date Apr 20 (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 USC00069388, 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.

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 12 – Mar 19Set out Mar 26 – Apr 16Start 4-6 wk before set-out; set out 3-6 wk before last frost.
BroccoliFeb 26 – Mar 26Set out Apr 9 – Apr 23Start 4-6 wk before set-out; set out 2-4 wk before last frost.
Brussels sproutFeb 26 – Mar 26Set out Apr 9 – Apr 23Start 4-6 wk before set-out; set out 2-4 wk before last frost.
CabbageFeb 26 – Mar 12Set out Apr 9Start 4-6 wk before set-out; set out 4 wk before last frost.
KaleFeb 26 – Mar 12Set out Apr 9Start 4-6 wk before set-out; set out 4 wk before last frost.
KohlrabiFeb 26 – Mar 12Set out Apr 9Start 4-6 wk before set-out; set out 4 wk before last frost.
LeekJan 29 – Feb 12Set out Apr 9Start 8-10 wk before set-out; set out 4 wk before last frost.
LettuceMar 5 – Mar 19Set out Apr 9 – Apr 16Start 4-5 wk before set-out; set out 3-4 wk before last frost.
OnionJan 29 – Feb 12Set out Apr 9Start 8-10 wk before set-out; set out 4 wk before last frost.
Radish—Sow Apr 9 – Apr 23Sow seed in garden 2-4 wk before last frost.
Turnip—Sow Apr 9 – Apr 23Sow seed in garden 2-4 wk before last frost.
ParsleyFeb 5 – Feb 19Set out Apr 16 – Apr 23Start 9-10 wk before set-out; set out 2-3 wk before last frost.
CauliflowerMar 12 – Mar 26Set out Apr 23Start 4-6 wk before set-out; set out 2 wk before last frost.
Potato—Sow Apr 23 – Apr 30Plant seed potatoes 1-2 wk before last frost.
Swiss chardMar 12 – Mar 26Set out Apr 23; or sow Apr 9Start 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 7Sow seed in garden after last frost.
CeleryFeb 12 – Feb 26Set out on/after May 7Start 10-12 wk before set-out; set out after last frost.
Parsnip—Sow on/after May 7Sow seed in garden after last frost.
CucumberApr 16 – Apr 30Set out May 14 – May 21
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 14 – May 21Plant slips (young plants) 1-2 wk after last frost.
TomatoMar 19 – Apr 9Set out May 14 – May 21Start 6-8 wk before set-out; set out 1-2 wk after last frost.
BasilMar 26 – Apr 9Set out May 21Start 6-8 wk before set-out; set out 2 wk after last frost.
EggplantMar 12 – Apr 2Set out May 21 – May 28Start 8-10 wk before set-out; set out 2-3 wk after last frost.
MelonApr 23 – Apr 30Set out May 21Start 3-4 wk before set-out; set out 2 wk after last frost.
PepperMar 12 – Mar 26Set out May 21Start 8-10 wk before set-out; set out 2 wk after last frost.
PumpkinApr 23 – Apr 30Set out May 21
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 23 – Apr 30Set out May 21
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 23 – Apr 30Set out May 21
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 23 – Apr 30Set out May 21
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 9; there is a 10% chance of one before Sep 30. 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 1 and 10% date Sep 20. UNH Extension notes many fall vegetables tolerate mild frosts down to about 28°F (median first 28°F here: Oct 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 360 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