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Frost dates for Durham 2 SSW, NH

NOAA weather station USW00054795 at 63 ft elevation. Based on 19 years within 1991-2020. Last verified 2026-10-17.

Last spring freeze (32°F)

May 7

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

May 13 30% risk · May 19 10% risk

First fall freeze (32°F)

Oct 4

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

Sep 23 10% chance of a freeze earlier than this

Freeze-free season

150 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)Jun 1 / May 24 / May 19Sep 11 / Sep 24
32°F (freeze)May 19 / May 13 / May 7Sep 23 / Oct 4
28°F (hard freeze)May 7 / Apr 29 / Apr 24Oct 2 / Oct 19

Also at 32°F, last-freeze 70% date May 2 and 90% date Apr 25 (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 USW00054795, 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.

UNH Extension says that for central New Hampshire, Memorial Day is a conservative estimate of the last frost date (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 18 – Mar 25Set out Apr 1 – Apr 22Start 4-6 wk before set-out; set out 3-6 wk before last frost.
BroccoliMar 4 – Apr 1Set out Apr 15 – Apr 29Start 4-6 wk before set-out; set out 2-4 wk before last frost.
Brussels sproutMar 4 – Apr 1Set out Apr 15 – Apr 29Start 4-6 wk before set-out; set out 2-4 wk before last frost.
CabbageMar 4 – Mar 18Set out Apr 15Start 4-6 wk before set-out; set out 4 wk before last frost.
KaleMar 4 – Mar 18Set out Apr 15Start 4-6 wk before set-out; set out 4 wk before last frost.
KohlrabiMar 4 – Mar 18Set out Apr 15Start 4-6 wk before set-out; set out 4 wk before last frost.
LeekFeb 4 – Feb 18Set out Apr 15Start 8-10 wk before set-out; set out 4 wk before last frost.
LettuceMar 11 – Mar 25Set out Apr 15 – Apr 22Start 4-5 wk before set-out; set out 3-4 wk before last frost.
OnionFeb 4 – Feb 18Set out Apr 15Start 8-10 wk before set-out; set out 4 wk before last frost.
Radish—Sow Apr 15 – Apr 29Sow seed in garden 2-4 wk before last frost.
Turnip—Sow Apr 15 – Apr 29Sow seed in garden 2-4 wk before last frost.
ParsleyFeb 11 – Feb 25Set out Apr 22 – Apr 29Start 9-10 wk before set-out; set out 2-3 wk before last frost.
CauliflowerMar 18 – Apr 1Set out Apr 29Start 4-6 wk before set-out; set out 2 wk before last frost.
Potato—Sow Apr 29 – May 6Plant seed potatoes 1-2 wk before last frost.
Swiss chardMar 18 – Apr 1Set out Apr 29; or sow Apr 15Start 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 13Sow seed in garden after last frost.
CeleryFeb 18 – Mar 4Set out on/after May 13Start 10-12 wk before set-out; set out after last frost.
Parsnip—Sow on/after May 13Sow seed in garden after last frost.
CucumberApr 22 – May 6Set out May 20 – May 27
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 20 – May 27Plant slips (young plants) 1-2 wk after last frost.
TomatoMar 25 – Apr 15Set out May 20 – May 27Start 6-8 wk before set-out; set out 1-2 wk after last frost.
BasilApr 1 – Apr 15Set out May 27Start 6-8 wk before set-out; set out 2 wk after last frost.
EggplantMar 18 – Apr 8Set out May 27 – Jun 3Start 8-10 wk before set-out; set out 2-3 wk after last frost.
MelonApr 29 – May 6Set out May 27Start 3-4 wk before set-out; set out 2 wk after last frost.
PepperMar 18 – Apr 1Set out May 27Start 8-10 wk before set-out; set out 2 wk after last frost.
PumpkinApr 29 – May 6Set out May 27
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 29 – May 6Set out May 27
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 29 – May 6Set out May 27
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 29 – May 6Set out May 27
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 4; there is a 10% chance of one before Sep 23. 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 Sep 24 and 10% date Sep 11. UNH Extension notes many fall vegetables tolerate mild frosts down to about 28°F (median first 28°F here: Oct 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 63 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