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Frost dates for Norwich Public Utility Plt, CT
NOAA weather station USC00065910 at 20 ft elevation. Based on 26 years within 1991-2020. Last verified 2026-10-17.
Last spring freeze (32°F)
Apr 14
median: freeze still happened after this date in half of years
Apr 21 30% risk · Apr 30 10% risk
First fall freeze (32°F)
Oct 24
median: a freeze had happened by this date in half of years
Oct 9 10% chance of a freeze earlier than this
Freeze-free season
192 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
| Threshold | Spring: latest-freeze date at risk of 10% / 30% / 50% | Fall: first-freeze date at chance of 10% / 50% |
|---|---|---|
| 36°F (frost possible) | May 13 / May 5 / Apr 30 | Oct 1 / Oct 12 |
| 32°F (freeze) | Apr 30 / Apr 21 / Apr 14 | Oct 9 / Oct 24 |
| 28°F (hard freeze) | Apr 16 / Apr 6 / Apr 1 | Oct 19 / Nov 5 |
Also at 32°F, last-freeze 70% date Apr 9 and 90% date Apr 1 (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 USC00065910, 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.
Showing the schedule for the 2027 season (dates repeat yearly). Table below defaults to Typical; it updates when you choose.
| Crop | Start seeds indoors | Outdoors | UNH Extension rule used |
|---|---|---|---|
| Spinach | Jan 27 – Mar 3 | Set out Mar 10 – Mar 31 | Start 4-6 wk before set-out; set out 3-6 wk before last frost. |
| Broccoli | Feb 10 – Mar 10 | Set out Mar 24 – Apr 7 | Start 4-6 wk before set-out; set out 2-4 wk before last frost. |
| Brussels sprout | Feb 10 – Mar 10 | Set out Mar 24 – Apr 7 | Start 4-6 wk before set-out; set out 2-4 wk before last frost. |
| Cabbage | Feb 10 – Feb 24 | Set out Mar 24 | Start 4-6 wk before set-out; set out 4 wk before last frost. |
| Kale | Feb 10 – Feb 24 | Set out Mar 24 | Start 4-6 wk before set-out; set out 4 wk before last frost. |
| Kohlrabi | Feb 10 – Feb 24 | Set out Mar 24 | Start 4-6 wk before set-out; set out 4 wk before last frost. |
| Leek | Jan 13 – Jan 27 | Set out Mar 24 | Start 8-10 wk before set-out; set out 4 wk before last frost. |
| Lettuce | Feb 17 – Mar 3 | Set out Mar 24 – Mar 31 | Start 4-5 wk before set-out; set out 3-4 wk before last frost. |
| Onion | Jan 13 – Jan 27 | Set out Mar 24 | Start 8-10 wk before set-out; set out 4 wk before last frost. |
| Radish | — | Sow Mar 24 – Apr 7 | Sow seed in garden 2-4 wk before last frost. |
| Turnip | — | Sow Mar 24 – Apr 7 | Sow seed in garden 2-4 wk before last frost. |
| Parsley | Jan 20 – Feb 3 | Set out Mar 31 – Apr 7 | Start 9-10 wk before set-out; set out 2-3 wk before last frost. |
| Cauliflower | Feb 24 – Mar 10 | Set out Apr 7 | Start 4-6 wk before set-out; set out 2 wk before last frost. |
| Potato | — | Sow Apr 7 – Apr 14 | Plant seed potatoes 1-2 wk before last frost. |
| Swiss chard | Feb 24 – Mar 10 | Set out Apr 7; or sow Mar 24 | Start 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 21 | Sow seed in garden after last frost. |
| Celery | Jan 27 – Feb 10 | Set out on/after Apr 21 | Start 10-12 wk before set-out; set out after last frost. |
| Parsnip | — | Sow on/after Apr 21 | Sow seed in garden after last frost. |
| Cucumber | Mar 31 – Apr 14 | Set out Apr 28 – May 5 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 28 – May 5 | Plant slips (young plants) 1-2 wk after last frost. |
| Tomato | Mar 3 – Mar 24 | Set out Apr 28 – May 5 | Start 6-8 wk before set-out; set out 1-2 wk after last frost. |
| Basil | Mar 10 – Mar 24 | Set out May 5 | Start 6-8 wk before set-out; set out 2 wk after last frost. |
| Eggplant | Feb 24 – Mar 17 | Set out May 5 – May 12 | Start 8-10 wk before set-out; set out 2-3 wk after last frost. |
| Melon | Apr 7 – Apr 14 | Set out May 5 | Start 3-4 wk before set-out; set out 2 wk after last frost. |
| Pepper | Feb 24 – Mar 10 | Set out May 5 | Start 8-10 wk before set-out; set out 2 wk after last frost. |
| Pumpkin | Apr 7 – Apr 14 | Set out May 5 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 squash | Apr 7 – Apr 14 | Set out May 5 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 squash | Apr 7 – Apr 14 | Set out May 5 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. |
| Zucchini | Apr 7 – Apr 14 | Set out May 5 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 15 | Sow 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 thaws | Sow seed in garden as soon as soil thaws. |
Fall: when the garden ends
At this station the median first 32°F freeze is Oct 24; there is a 10% chance of one before Oct 9. 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 12 and 10% date Oct 1. UNH Extension notes many fall vegetables tolerate mild frosts down to about 28°F (median first 28°F here: Nov 5), 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 20 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
- Groton, CT: 12 mi away, 40 ft elevation, median last 32°F freeze Apr 8
- Groton NEw London AP, CT: 14 mi away, 10 ft elevation, median last 32°F freeze Apr 16
- Willimantic Windham AP, CT: 16 mi away, 247 ft elevation, median last 32°F freeze Apr 28
- Hampton, CT: 17 mi away, 490 ft elevation, median last 32°F freeze Apr 30
- Westerly State AP, RI: 18 mi away, 81 ft elevation, median last 32°F freeze Apr 11