Fall in zone 7aPhoto: Dietmar Rabich, CC BY-SA 4.0, via Wikimedia Commons
Frost dates for ZIP 06378 (Stonington, CT)
Average last spring and first fall frost dates with 10%, 50% and 90% odds, from NOAA's 1991–2020 climate normals for the nearest weather station, Westerly State AP, RI (6 miles away).
- Average last spring frostApr 1150% chance of a 32°F freeze after this date
- Average first fall frostOct 3150% chance of a 32°F freeze by this date
- Growing season (frost-free)201 daysmedian, 32°F threshold
- USDA hardiness zone7a0 to 5°F avg. coldest night
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This week in your yard
As of Oct 18, 2026, from your frost dates, zone and soil temperature. Lawn timing · Vegetables · Pruning · Plants
Soil temperature now
2-inch depth
57°F 55°F or warmer
24-hour average · latest 53°F, as of Oct 18, 2:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Kingston 1 W (20 mi), Kingston 1 NW (20 mi).
4-inch depth
58°F 55°F or warmer
24-hour average · latest 56°F, as of Oct 18, 2:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Kingston 1 W (20 mi), Kingston 1 NW (20 mi).
Fall: Texas A&M AgriLife times fall pre-emergent (for winter weeds such as annual bluegrass) to soil cooling to about 70°F for several days. The 50–55°F band is the spring trigger. Always read and follow the product label.
7-day forecast and frost risk
The latest National Weather Service 7-day forecast and any Frost Advisory or Freeze Warning for 06378 load here. You can also open the NWS forecast for this ZIP.
Pre-emergent
Soil is 58°F at 4 inches (estimated soil temperature, not a station reading). Fall pre-emergent (annual bluegrass, winter weeds): window open as soil cools through the 70s and 60s.
Fertilizer window
Lawn region: North (cool-season). Timing only; always follow the product label.
- Kentucky bluegrass (cool-season): Early fall: Around Labor Day (late August–September); Late fall: Late October–November, before the ground freezes; Late spring: Optional around Memorial Day. Avoid: Early-spring and midsummer feeding (pushes top growth, favors crabgrass).
Plant now
No vegetable planting windows are open this week.
Prune now
No frost-timed pruning windows are open this week.
Your average first frost is Oct 31: skip heavy pruning in the 6–8 weeks before it, because new growth may not harden off in time.
Spring-flowering shrubs are pruned right after their flowers fade, not by date. See the pruning guide.
Last spring frost odds
| Chance of a 32°F freeze after this date | Date |
|---|---|
| 90% (early: most years still freeze after this) | Mar 31 |
| 50% (the "average" last frost) | Apr 11 |
| 10% (cautious: only 1 year in 10 freezes later) | Apr 26 |
Most gardeners plant frost-tender crops (tomatoes, peppers, basil) after the 50% date, and closer to the 10% date for less risk.
First fall frost odds
| Chance the first 32°F freeze has happened by this date | Date |
|---|---|
| 10% (early: 1 year in 10 freezes this soon) | Oct 16 |
| 50% (the "average" first frost) | Oct 31 |
| 90% (late: most years have frozen by now) | Nov 12 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | Apr 27 | Oct 17 |
| 32°F (freeze) | Apr 11 | Oct 31 |
| 28°F (hard freeze) | Mar 29 | Nov 11 |
n/a means NOAA did not publish a date at that threshold for this station (usually because it rarely gets that cold).
Vegetable planting calendar for 06378
Dates count from your average last spring frost (Apr 11) and first fall frost (Oct 31). Half of years have a frost after the spring date, so give tender crops (tomatoes, peppers, squash) some slack.
| Crop | Start indoors | Spring planting | Fall planting |
|---|---|---|---|
| Tomato | Feb 14–28 | Apr 18–May 2 (transplant) | – |
| Pepper (sweet and hot) | Jan 31–Feb 14 | Apr 25–May 9 (transplant) | – |
| Eggplant | Jan 31–Feb 14 | Apr 25–May 9 (transplant) | – |
| Tomatillo | Feb 14–28 | Apr 18–May 2 (transplant) | – |
| Lettuce | Feb 14–28 | Mar 21–Apr 11 (transplant) Mar 14–Apr 25 (sow outdoors) | Sep 5–26 (transplant) Aug 22–Sep 19 (sowing) |
| Spinach | – | Feb 28–Mar 21 (sow outdoors) | Sep 5–26 (sowing) |
| Kale | Feb 14–28 | Mar 14–28 (transplant) Mar 14–28 (sow outdoors) | Aug 8–Sep 5 (transplant) Jul 25–Aug 22 (sowing) |
| Collards | Feb 14–28 | Mar 14–Apr 11 (transplant) Mar 14–Apr 11 (sow outdoors) | Aug 8–Sep 5 (transplant) Jul 25–Aug 22 (sowing) |
| Broccoli | Jan 31–Feb 14 | Mar 14–28 (transplant) | Jul 25–Aug 22 (transplant) |
| Cabbage | Jan 31–Feb 14 | Mar 14–28 (transplant) | Jul 25–Aug 22 (transplant) |
| Cauliflower | Jan 31–Feb 14 | Mar 28–Apr 11 (transplant) | Jul 25–Aug 22 (transplant) |
| Brussels sprouts | Jan 17–31 | Mar 14–28 (transplant) | Jul 11–Aug 1 (transplant) |
| Kohlrabi | Feb 14–28 | Mar 14–28 (transplant) Mar 14–28 (sow outdoors) | Aug 22–Sep 5 (sowing) |
| Bok choy / Asian greens | – | Mar 14–28 (sow outdoors) | Sep 5–19 (sowing) |
| Arugula | – | Mar 14–Apr 11 (sow outdoors) | Sep 5–Oct 3 (sowing) |
| Mustard greens | – | Mar 14–Apr 4 (sow outdoors) | Sep 5–19 (sowing) |
| Swiss chard | Feb 28–Mar 14 | Mar 28–Apr 18 (transplant) Mar 28–Apr 25 (sow outdoors) | Aug 22–Sep 5 (sowing) |
| Beet | – | Mar 14–Apr 11 (sow outdoors) | Aug 22–Sep 5 (sowing) |
| Carrot | – | Mar 21–Apr 18 (sow outdoors) | Aug 8–22 (sowing) |
| Radish | – | Mar 7–Apr 18 (sow outdoors) | Sep 19–Oct 3 (sowing) |
| Turnip | – | Mar 14–Apr 4 (sow outdoors) | Aug 22–Sep 5 (sowing) |
| Parsnip | – | Mar 21–Apr 11 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Feb 14–Mar 14 (sow outdoors) | Aug 8–22 (sowing) |
| Onion (bulbing) | Jan 17–31 | Feb 28–Mar 14 (transplant) | – |
| Green onion / scallion | – | Feb 28–Mar 28 (sow outdoors) | Aug 22–Sep 5 (sowing) |
| Leek | Jan 17–31 | Mar 14–28 (transplant) | – |
| Garlic | – | – | Sep 19–Oct 17 (sowing) |
| Shallot | – | Feb 28–Mar 14 (transplant) | Sep 19–Oct 17 (sowing) |
| Potato | – | Mar 14–28 (transplant) | Jul 11–25 (transplant) |
| Sweet potato | – | May 2–16 (transplant) | – |
| Sweet corn | – | Apr 18–May 2 (sow outdoors) | – |
| Bean, bush (snap) | – | Apr 18–May 2 (sow outdoors) | – |
| Bean, pole | – | Apr 18–May 2 (sow outdoors) | – |
| Lima bean | – | Apr 25–May 9 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | May 2–23 (sow outdoors) | – |
| Cucumber | Mar 14–21 | Apr 18–May 2 (transplant) Apr 18–May 2 (sow outdoors) | – |
| Summer squash / zucchini | Mar 14–21 | Apr 18–May 2 (transplant) Apr 18–May 2 (sow outdoors) | – |
| Winter squash | Mar 14–21 | Apr 18–May 2 (transplant) Apr 18–May 2 (sow outdoors) | – |
| Pumpkin | – | Apr 18–May 2 (sow outdoors) | – |
| Watermelon | Mar 14–21 | Apr 25–May 9 (transplant) Apr 25–May 9 (sow outdoors) | – |
| Cantaloupe / muskmelon | Mar 14–21 | Apr 25–May 9 (transplant) Apr 25–May 9 (sow outdoors) | – |
| Okra | Feb 28–Mar 14 | Apr 25–May 9 (transplant) Apr 25–May 9 (sow outdoors) | – |
| Celery | Jan 17–31 | Apr 18–25 (transplant) | – |
| Basil | Feb 28–Mar 14 | Apr 18–May 2 (transplant) Apr 18–May 2 (sow outdoors) | – |
| Cilantro | – | Mar 28–Apr 25 (sow outdoors) | Sep 5–19 (sowing) |
| Parsley | Jan 31–Feb 14 | Mar 28–Apr 11 (transplant) Mar 21–Apr 11 (sow outdoors) | – |
| Dill | – | Apr 11–25 (sow outdoors) | Sep 5–19 (sowing) |
| Sunflower | – | Apr 11–25 (sow outdoors) | – |
| Asparagus (crowns) | – | Mar 14–28 (transplant) | – |
| Rhubarb (crowns) | – | Mar 14–28 (transplant) | – |
| Strawberry (plants) | – | Mar 14–28 (transplant) | Aug 22–Sep 19 (transplant) |
Typical ranges from university extension planting calendars, adjusted to your frost dates. Probabilities, not guarantees. Fall windows that would overlap spring planting are left out, as are fall crops of frost-tender plants where the frost-free season is under 210 days.
Where these numbers come from
Station: Westerly State AP, RI (NOAA GHCN-Daily ID USW00014794), elevation 81 ft, 6.2 miles from the ZIP's center point. NOAA completeness flag: R (representative, 10+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Groton, CT | 7 mi | Apr 8 | Nov 2 |
| Groton New London AP, CT | 8 mi | Apr 16 | Oct 28 |
| Norwich Public Utility Plt, CT | 13 mi | Apr 14 | Oct 24 |
The average last-frost dates of these stations span 8 days, a rough guide to local variation. See data sources & methods.
Frost questions for 06378
When is the last frost in 06378?
The average (50% chance) last spring freeze of 32°F for ZIP 06378 is April 11. For a more cautious planting date, use April 26, when only 1 year in 10 still sees a later freeze.
When is the first frost in 06378?
The average first fall freeze is October 31. In 1 year in 10 it comes by October 16.
What hardiness zone is 06378?
ZIP 06378 is in USDA zone 7a (0 to 5°F average coldest winter night), per the 2023 USDA Plant Hardiness Zone Map ZIP listing.
What is the soil temperature in 06378 right now?
This page shows the latest 2-inch and 4-inch soil temperature from the nearest public soil station (USDA SCAN, NOAA USCRN or TexMesonet), or a labeled estimate when no station is close, against the 50–55°F spring pre-emergent band.
Nearby ZIP codes
06379 Pawcatuck 06355 Old Mystic 06339 06359 02891 Westerly 06338 Mashantucket 06390 Fishers Island 06340 Conning Towers-Nautilus Park
Other ZIP codes in New London County
06249 06254 06320 06330 06333 06334 06335 06336 06338 06339 06340 06350 06351 06353 06355 06357 06359 06360 06365 06370 06371 06375 06376 06379 All New London County frost dates · Connecticut frost dates
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Free. One weekly email plus alerts when your ZIP has a frost or a soil-temperature change worth acting on. After you submit, Kit (our email provider) sends a confirmation email: check your email and click the link to confirm. You aren't subscribed until you do. We collect only your email address and ZIP, sent to Kit to deliver The Dial. Unsubscribe anytime.