Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for Bristol, CT

Bristol, CT is in USDA zone 6b across its 2 ZIP codes. The median last spring frost is April 25 and the first fall frost October 18.

Bristol on the zone map

Outlined: its 1 ZIP code areas · 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

ZIP codes2

Last frostApr 25

First frostOct 18

Growing season172 days

6b 2 ZIPs

Frost forecast — next 7 nights

live from the National Weather Service

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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 Bristol, CT

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostApril 25median — 50% chance of a later frost

Safe for tender plantsMay 10only 10% chance of frost after

First fall frostOctober 18median — 10% chance by Oct 4

Growing season172 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 13 and returns around October 30.

From the NOAA station Burlington, CT, elevation 505 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 Bristol

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 14 – Mar 28

SpinachSow outdoors · Mar 14 – Apr 4

Broccoli, cabbageStart indoors · Feb 14 – Feb 28

Broccoli, cabbageTransplant · Apr 4 – Apr 18

Onion setsPlant outdoors · Mar 28 – Apr 11

PotatoesPlant outdoors · Apr 4 – Apr 18

LettuceSow outdoors · Mar 28 – Apr 11

Carrots, beetsSow outdoors · Apr 4 – Apr 18

TomatoesStart indoors · Feb 28 – Mar 14

TomatoesTransplant · May 2 – May 16

Peppers, eggplantStart indoors · Feb 14 – Feb 28

Peppers, eggplantTransplant · May 9 – May 23

BeansSow outdoors · May 2 – May 16

Sweet cornSow outdoors · May 2 – May 16

Cucumbers, squashSow outdoors · May 2 – May 16

Fall lettuce, spinachSow outdoors · Aug 23 – Sep 6

GarlicPlant cloves · Oct 4 – Nov 8

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 25) and first fall frost (Oct 18) 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 06010 came on Apr 3 — 6 days earlier than the 1991–2020 average (Apr 9).

average
Apr 92026
Apr 3

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.

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 Bristol, CT.

Soil in Bristol, CT

The soil mapped at the center of ZIP 06010 is Charlton — fine sandy loam, well drained.

TextureFine sandy loamdrains and warms fast; dries out and needs more feeding

pH5.1strongly acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter8%high

Hydrologic groupBwater soaks in moderately

Farmland classNot prime farmlandUSDA classification

Map unit: Charlton-Urban land complex, 8 to 15 percent slopes.

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 06010; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Bristol, CT

Summer high84 °Faverage high, July

Winter low17 °Faverage low, January

Hot days13days a year at 90 °F or more

Freezing nights142nights a year at 32 °F or less

Growing degree days2,830base 50 °F — the season’s usable heat

Longest day15 h 12 mindaylight on June 21

Shortest day9 h 09 mindaylight on December 21

Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)

Precipitation52 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Burlington, CT (8 mi away); precipitation: Thomaston Dam, CT (6 mi away). Daylight is calculated from latitude.

ZIP codes in Bristol

Connecticut planting zones →

Questions about Bristol

What planting zone is Bristol, CT?

Bristol, CT is in USDA hardiness zone 6b on the 2023 map (6b: −5 to 0 °F).

When is the last frost in Bristol, CT?

The median last spring frost is April 25 and the median first fall frost is October 18 (NOAA 1991–2020 normals, Burlington station).

When can I plant a garden in Bristol, CT?

Cool-season crops like peas and spinach go in around Mar 14 – Apr 4; tomatoes, peppers, beans and squash after about May 2, once frost risk has passed.

What kind of onions grow in Bristol, CT?

Long-day onions: the longest day is 15 h 12 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

How much rain and snow does Bristol, CT get?

About 52 inches of precipitation a year (NOAA 1991–2020 normals).