Fall in zone 7aPhoto: Dietmar Rabich, CC BY-SA 4.0, via Wikimedia Commons
Frost dates for ZIP 06355 (Old Mystic, 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, Groton, CT (4 miles away).
- Average last spring frostApr 850% chance of a 32°F freeze after this date
- Average first fall frostNov 250% chance of a 32°F freeze by this date
- Growing season (frost-free)207 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 (24 mi), Kingston 1 NW (24 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 (24 mi), Kingston 1 NW (24 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 06355 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
Prune now
No frost-timed pruning windows are open this week.
Your average first frost is Nov 2: 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 28 |
| 50% (the "average" last frost) | Apr 8 |
| 10% (cautious: only 1 year in 10 freezes later) | Apr 22 |
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 18 |
| 50% (the "average" first frost) | Nov 2 |
| 90% (late: most years have frozen by now) | Nov 15 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | Apr 22 | Oct 21 |
| 32°F (freeze) | Apr 8 | Nov 2 |
| 28°F (hard freeze) | Mar 29 | Nov 14 |
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 06355
Dates count from your average last spring frost (Apr 8) and first fall frost (Nov 2). 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 11–25 | Apr 15–29 (transplant) | – |
| Pepper (sweet and hot) | Jan 28–Feb 11 | Apr 22–May 6 (transplant) | – |
| Eggplant | Jan 28–Feb 11 | Apr 22–May 6 (transplant) | – |
| Tomatillo | Feb 11–25 | Apr 15–29 (transplant) | – |
| Lettuce | Feb 11–25 | Mar 18–Apr 8 (transplant) Mar 11–Apr 22 (sow outdoors) | Sep 7–28 (transplant) Aug 24–Sep 21 (sowing) |
| Spinach | – | Feb 25–Mar 18 (sow outdoors) | Sep 7–28 (sowing) |
| Kale | Feb 11–25 | Mar 11–25 (transplant) Mar 11–25 (sow outdoors) | Aug 10–Sep 7 (transplant) Jul 27–Aug 24 (sowing) |
| Collards | Feb 11–25 | Mar 11–Apr 8 (transplant) Mar 11–Apr 8 (sow outdoors) | Aug 10–Sep 7 (transplant) Jul 27–Aug 24 (sowing) |
| Broccoli | Jan 28–Feb 11 | Mar 11–25 (transplant) | Jul 27–Aug 24 (transplant) |
| Cabbage | Jan 28–Feb 11 | Mar 11–25 (transplant) | Jul 27–Aug 24 (transplant) |
| Cauliflower | Jan 28–Feb 11 | Mar 25–Apr 8 (transplant) | Jul 27–Aug 24 (transplant) |
| Brussels sprouts | Jan 14–28 | Mar 11–25 (transplant) | Jul 13–Aug 3 (transplant) |
| Kohlrabi | Feb 11–25 | Mar 11–25 (transplant) Mar 11–25 (sow outdoors) | Aug 24–Sep 7 (sowing) |
| Bok choy / Asian greens | – | Mar 11–25 (sow outdoors) | Sep 7–21 (sowing) |
| Arugula | – | Mar 11–Apr 8 (sow outdoors) | Sep 7–Oct 5 (sowing) |
| Mustard greens | – | Mar 11–Apr 1 (sow outdoors) | Sep 7–21 (sowing) |
| Swiss chard | Feb 25–Mar 11 | Mar 25–Apr 15 (transplant) Mar 25–Apr 22 (sow outdoors) | Aug 24–Sep 7 (sowing) |
| Beet | – | Mar 11–Apr 8 (sow outdoors) | Aug 24–Sep 7 (sowing) |
| Carrot | – | Mar 18–Apr 15 (sow outdoors) | Aug 10–24 (sowing) |
| Radish | – | Mar 4–Apr 15 (sow outdoors) | Sep 21–Oct 5 (sowing) |
| Turnip | – | Mar 11–Apr 1 (sow outdoors) | Aug 24–Sep 7 (sowing) |
| Parsnip | – | Mar 18–Apr 8 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Feb 11–Mar 11 (sow outdoors) | Aug 10–24 (sowing) |
| Onion (bulbing) | Jan 14–28 | Feb 25–Mar 11 (transplant) | – |
| Green onion / scallion | – | Feb 25–Mar 25 (sow outdoors) | Aug 24–Sep 7 (sowing) |
| Leek | Jan 14–28 | Mar 11–25 (transplant) | – |
| Garlic | – | – | Sep 21–Oct 19 (sowing) |
| Shallot | – | Feb 25–Mar 11 (transplant) | Sep 21–Oct 19 (sowing) |
| Potato | – | Mar 11–25 (transplant) | Jul 13–27 (transplant) |
| Sweet potato | – | Apr 29–May 13 (transplant) | – |
| Sweet corn | – | Apr 15–29 (sow outdoors) | – |
| Bean, bush (snap) | – | Apr 15–29 (sow outdoors) | – |
| Bean, pole | – | Apr 15–29 (sow outdoors) | – |
| Lima bean | – | Apr 22–May 6 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | Apr 29–May 20 (sow outdoors) | – |
| Cucumber | Mar 11–18 | Apr 15–29 (transplant) Apr 15–29 (sow outdoors) | – |
| Summer squash / zucchini | Mar 11–18 | Apr 15–29 (transplant) Apr 15–29 (sow outdoors) | – |
| Winter squash | Mar 11–18 | Apr 15–29 (transplant) Apr 15–29 (sow outdoors) | – |
| Pumpkin | – | Apr 15–29 (sow outdoors) | – |
| Watermelon | Mar 11–18 | Apr 22–May 6 (transplant) Apr 22–May 6 (sow outdoors) | – |
| Cantaloupe / muskmelon | Mar 11–18 | Apr 22–May 6 (transplant) Apr 22–May 6 (sow outdoors) | – |
| Okra | Feb 25–Mar 11 | Apr 22–May 6 (transplant) Apr 22–May 6 (sow outdoors) | – |
| Celery | Jan 14–28 | Apr 15–22 (transplant) | – |
| Basil | Feb 25–Mar 11 | Apr 15–29 (transplant) Apr 15–29 (sow outdoors) | – |
| Cilantro | – | Mar 25–Apr 22 (sow outdoors) | Sep 7–21 (sowing) |
| Parsley | Jan 28–Feb 11 | Mar 25–Apr 8 (transplant) Mar 18–Apr 8 (sow outdoors) | – |
| Dill | – | Apr 8–22 (sow outdoors) | Sep 7–21 (sowing) |
| Sunflower | – | Apr 8–22 (sow outdoors) | – |
| Asparagus (crowns) | – | Mar 11–25 (transplant) | – |
| Rhubarb (crowns) | – | Mar 11–25 (transplant) | – |
| Strawberry (plants) | – | Mar 11–25 (transplant) | Aug 24–Sep 21 (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: Groton, CT (NOAA GHCN-Daily ID USC00063207), elevation 40 ft, 3.6 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 New London AP, CT | 5 mi | Apr 16 | Oct 28 |
| Westerly State AP, RI | 9 mi | Apr 11 | Oct 31 |
| Norwich Public Utility Plt, CT | 12 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 06355
When is the last frost in 06355?
The average (50% chance) last spring freeze of 32°F for ZIP 06355 is April 8. For a more cautious planting date, use April 22, when only 1 year in 10 still sees a later freeze.
When is the first frost in 06355?
The average first fall freeze is November 2. In 1 year in 10 it comes by October 18.
What hardiness zone is 06355?
ZIP 06355 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 06355 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
06378 Stonington 06340 Conning Towers-Nautilus Park 06339 06390 Fishers Island 06379 Pawcatuck 06335 Gales Ferry 06338 Mashantucket 06320 New London
Other ZIP codes in New London County
06249 06254 06320 06330 06333 06334 06335 06336 06338 06339 06340 06350 06351 06353 06357 06359 06360 06365 06370 06371 06375 06376 06378 06379 All New London County frost dates · Connecticut frost dates
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Weekly yard timing, plus frost and soil-temperature alerts for your ZIP code.
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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.