Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated

Planting zone for 06359 — North Stonington, CT

ZIP code 06359 (North Stonington, Southeastern Connecticut County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is April 11 and the first fall frost October 31.

Where ZIP 06359 is

Outlined: the ZIP code area · tap the map for the zone at any spot · scroll or pinch to zoom

Not the official USDA Plant Hardiness Zone Map. Zones come from the 2023 USDA hardiness-zone data by the PRISM Group, Oregon State University; we re-mapped and recolored them. The official map is at planthardiness.ars.usda.gov.

Zone6b−5 to 0 °F
Coldest night−20.6 to −17.8 °C
Last frostApr 11
First frostOct 31
2012 zone6b

Same zone as on the 2012 map. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 6b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for North Stonington, CT…

Forecast data: National Weather Service (api.weather.gov), public domain. This is not a warning service — for official frost and freeze warnings see weather.gov.

Frost dates in North Stonington, CT

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 11median — 50% chance of a later frost
Safe for tender plantsApril 26only 10% chance of frost after
First fall frostOctober 31median — 10% chance by Oct 16
Growing season201 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 29 and returns around November 11.

From the NOAA station Westerly State Airport, RI — 9 miles away, elevation 82 ft. NOAA NCEI U.S. Climate Normals 1991–2020, 32 °F threshold. Low spots and valleys can freeze later in spring than the station.

When to plant vegetables in 06359

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Feb 28 – Mar 14
SpinachSow outdoors · Feb 28 – Mar 21
Broccoli, cabbageStart indoors · Jan 31 – Feb 14
Broccoli, cabbageTransplant · Mar 21 – Apr 4
Onion setsPlant outdoors · Mar 14 – Mar 28
PotatoesPlant outdoors · Mar 21 – Apr 4
LettuceSow outdoors · Mar 14 – Mar 28
Carrots, beetsSow outdoors · Mar 21 – Apr 4
TomatoesStart indoors · Feb 14 – Feb 28
TomatoesTransplant · Apr 18 – May 2
Peppers, eggplantStart indoors · Jan 31 – Feb 14
Peppers, eggplantTransplant · Apr 25 – May 9
BeansSow outdoors · Apr 18 – May 2
Sweet cornSow outdoors · Apr 18 – May 2
Cucumbers, squashSow outdoors · Apr 18 – May 2
Fall lettuce, spinachSow outdoors · Sep 5 – Sep 19
GarlicPlant cloves · Oct 17 – Nov 21
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 11) and first fall frost (Oct 31) with the rules of thumb U.S. extension services publish. Cool-season crops take a light frost; warm-season crops do best once the soil is above about 60 °F.

When spring arrived in 2026

In 2026, spring leaf-out near 06359 came on Apr 5 — about the same time as the 1991–2020 average (Apr 5).

JanFebMarAprMayJun

The Spring Index marks the day when accumulated warmth is enough for lilac and honeysuckle to leaf out — a widely used signal that the growing season has started. Source: USA National Phenology Network, www.usanpn.org — Spring Indices, first leaf, 2026 (data as of 2026-09-08) and 30-year average 1991–2020 (CC BY 4.0).

Native plants for zone 6b in Connecticut

533 plants native to the lower 48 states, recorded in Connecticut, and rated by the USDA to survive −5 °F or colder — the bottom of zone 6b. Each links to its USDA PLANTS profile.

Trees 64

American basswood100 ft · blooms late spring · low shade tolerance · to −46 °FAmerican beech80 ft · blooms mid spring · low shade tolerance · to −44 °FAmerican chestnut115 ft · blooms early summer · high shade tolerance · to −33 °FAmerican elm120 ft · blooms early spring · medium shade tolerance · to −46 °FAmerican sycamore100 ft · blooms spring · medium shade tolerance · to −34 °Farborvitae50 ft · blooms mid spring · medium shade tolerance · to −33 °F

Shrubs 105

alderleaf buckthorn3 ft · blooms late spring · low shade tolerance · to −33 °FAllegheny serviceberry35 ft · blooms early spring · low shade tolerance · to −38 °Falternateleaf dogwood25 ft · blooms mid spring · low shade tolerance · to −47 °FAmerican black currant3 ft · blooms early spring · to −46 °FAmerican hazelnut10 ft · blooms spring · medium shade tolerance · to −33 °FAmerican holly40 ft · blooms mid spring · low shade tolerance · to −20 °F

Wildflowers & perennials 187

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °FAmerican bur-reed3 ft · blooms indeterminate · medium shade tolerance · to −33 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °FAmerican licorice4 ft · blooms late spring · medium shade tolerance · to −38 °FAmerican lotus3 ft · blooms mid summer · high shade tolerance · to −36 °FAmerican pokeweed7 ft · blooms mid summer · low shade tolerance · to −33 °F

Grasses 151

American beachgrass2.5 ft · blooms spring · high shade tolerance · to −28 °Farctic brome3 ft · blooms early summer · low shade tolerance · to −33 °FAtlantic mannagrass3 ft · blooms summer · low shade tolerance · to −8 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °FBailey's sedge2.1 ft · blooms late spring · low shade tolerance · to −33 °Fbeaked spikerush3 ft · blooms late spring · high shade tolerance · to −28 °F

Vines 9

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °Fcatbird grape30 ft · blooms late spring · medium shade tolerance · to −13 °Fdevil's darning needles15 ft · blooms mid summer · medium shade tolerance · to −38 °Fheartleaf peppervine2 ft · blooms late spring · low shade tolerance · to −8 °Friverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °Fsummer grape30 ft · blooms late spring · low shade tolerance · to −23 °F

Source: USDA, NRCS. 2026. The PLANTS Database (plants.usda.gov), National Plant Data Team — state distribution, native status and the “Temperature, Minimum” characteristic. Check light, moisture and soil needs before buying; local nurseries and your state native plant society can confirm what thrives in North Stonington, CT.

Soil in North Stonington, CT

The soil mapped at the center of ZIP 06359 is Woodbridge — moderately decomposed plant material, moderately well drained.

TextureModerately decomposed plant materialtop layer
DrainageModerately well drainednatural drainage class
Organic matter95%high
Hydrologic groupC/Dslow when drained; wet otherwise
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Woodbridge fine sandy loam, 0 to 8 percent slopes, very stony.

Soil Survey Staff, Natural Resources Conservation Service, USDA. Soil Survey Geographic (SSURGO) Database, via Soil Data Access, accessed 2026-10-29. The soil at the center point of ZIP 06359; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in North Stonington, CT

Summer high82 °Faverage high, July
Winter low25 °Faverage low, January
Hot days3days a year at 90 °F or more
Freezing nights109nights a year at 32 °F or less
Growing degree days3,008base 50 °F — the season’s usable heat
Longest day15 h 11 mindaylight on June 21
Shortest day9 h 10 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation47.3 inper year, rain and melted snow

Average high and low, by month

10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 40 °F, low 25 °F 40°25° JanFebruary: average high 41 °F, low 26 °F 41°26° FebMarch: average high 47 °F, low 32 °F 47°32° MarApril: average high 57 °F, low 41 °F 57°41° AprMay: average high 67 °F, low 50 °F 67°50° MayJune: average high 75 °F, low 59 °F 75°59° JunJuly: average high 82 °F, low 66 °F 82°66° JulAugust: average high 81 °F, low 64 °F 81°64° AugSeptember: average high 74 °F, low 57 °F 74°57° SepOctober: average high 64 °F, low 47 °F 64°47° OctNovember: average high 54 °F, low 38 °F 54°38° NovDecember: average high 45 °F, low 30 °F 45°30° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 3.81 in precipitation 3.8 JanFebruary: 3.38 in precipitation 3.4 FebMarch: 4.69 in precipitation 4.7 MarApril: 4.15 in precipitation 4.2 AprMay: 3.48 in precipitation 3.5 MayJune: 3.82 in precipitation 3.8 JunJuly: 3.09 in precipitation 3.1 JulAugust: 3.93 in precipitation 3.9 AugSeptember: 4.15 in precipitation 4.2 SepOctober: 4.27 in precipitation 4.3 OctNovember: 3.86 in precipitation 3.9 NovDecember: 4.71 in precipitation 4.7 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Westerly State Airport, RI (9 mi away); precipitation: Stonington 1.4 Nnw, CT (8 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

3 of the 8 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

028336b
Hopkinton, RI · 5 mi
063386b
Mashantucket, CT · 5 mi
028046b
Ashaway, RI · 6 mi
063787a
Stonington, CT · 6 mi
028736b
Rockville, RI · 6 mi
063396b
Ledyard, CT · 6 mi
063727a
Old Mystic, CT · 7 mi
063797a
Pawcatuck, CT · 7 mi

Connecticut planting zones →

Questions about 06359

What planting zone is ZIP code 06359?

ZIP code 06359 (North Stonington, CT) is in USDA hardiness zone 6b on the 2023 map: the coldest night of an average winter reaches −5 to 0 °F (−20.6 to −17.8 °C).

When is the last frost in North Stonington, CT?

The median last spring frost (32 °F) near 06359 is April 11; after April 26 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Westerly State Airport station.

When is the first frost in North Stonington, CT?

The median first fall frost near 06359 is October 31, giving a median frost-free growing season of 201 days.

When should I plant tomatoes in 06359?

Start tomato seeds indoors around Feb 14 – Feb 28 and set transplants outside around Apr 18 – May 2, one to three weeks after the median last frost.

How much rain and snow does 06359 get?

About 47.3 inches of precipitation a year (NOAA 1991–2020 normals, Stonington 1.4 Nnw station).

How hot do summers get in North Stonington, CT?

The average high peaks at 82 °F in July, with about 3 days a year at 90 °F or more.

What kind of soil does 06359 have?

The USDA soil survey maps Woodbridge at the center of ZIP 06359: moderately decomposed plant material, moderately well drained.

Did spring come early in North Stonington, CT in 2026?

Spring leaf-out near 06359 came on Apr 5 in 2026, about the same as the 1991–2020 average (Apr 5), according to the USA National Phenology Network Spring Index.

What kind of onions grow in North Stonington, CT?

Long-day onions: the longest day near 06359 is 15 h 11 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).