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

Planting zone for Fairfield, CT

Fairfield, CT is in USDA zone 7a across its 3 ZIP codes. The median last spring frost is April 5 and the first fall frost November 6.

Fairfield on the zone map

Outlined: its 2 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.

Zone7a0 to 5 °F
ZIP codes3
Last frostApr 5
First frostNov 6
Growing season216 days

7a 3 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 Fairfield, CT

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 5median — 50% chance of a later frost
Safe for tender plantsApril 17only 10% chance of frost after
First fall frostNovember 6median — 10% chance by Oct 25
Growing season216 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 26 and returns around November 19.

From the NOAA station Bridgeport Sikorsky Mem Airport, CT, elevation 7 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 Fairfield

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Feb 22 – Mar 8
SpinachSow outdoors · Feb 22 – Mar 15
Broccoli, cabbageStart indoors · Jan 25 – Feb 8
Broccoli, cabbageTransplant · Mar 15 – Mar 29
Onion setsPlant outdoors · Mar 8 – Mar 22
PotatoesPlant outdoors · Mar 15 – Mar 29
LettuceSow outdoors · Mar 8 – Mar 22
Carrots, beetsSow outdoors · Mar 15 – Mar 29
TomatoesStart indoors · Feb 8 – Feb 22
TomatoesTransplant · Apr 12 – Apr 26
Peppers, eggplantStart indoors · Jan 25 – Feb 8
Peppers, eggplantTransplant · Apr 19 – May 3
BeansSow outdoors · Apr 12 – Apr 26
Sweet cornSow outdoors · Apr 12 – Apr 26
Cucumbers, squashSow outdoors · Apr 12 – Apr 26
Fall lettuce, spinachSow outdoors · Sep 11 – Sep 25
GarlicPlant cloves · Oct 23 – Nov 27
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 5) and first fall frost (Nov 6) 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 06828 came on Apr 1 — about the same time as the 1991–2020 average (Apr 1).

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 7a in Connecticut

546 plants native to the lower 48 states, recorded in Connecticut, and rated by the USDA to survive 0 °F or colder — the bottom of zone 7a. Each links to its USDA PLANTS profile.

Trees 65

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 106

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 191

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 157

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 10

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °FAmerican wisteria50 ft · blooms spring · low shade tolerance · to −3 °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 °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 Fairfield, CT.

Soil in Fairfield, CT

The soil mapped at the center of ZIP 06828 is Udorthents — loam, poorly drained. Much of the area is built over (urban land); this is the natural soil underneath.

TextureLoama good balance for most vegetables
pH5.6moderately acidic; most vegetables like 6.0–7.0
DrainagePoorly drainedconsider raised beds
Organic matter4%moderate
Hydrologic groupBwater soaks in moderately
Farmland classNot prime farmlandUSDA classification

Map unit: Urban land.

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 06828; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Fairfield, CT

Summer high83 °Faverage high, July
Winter low24 °Faverage low, January
Hot days9days a year at 90 °F or more
Freezing nights92nights a year at 32 °F or less
Growing degree days3,347base 50 °F — the season’s usable heat
Longest day15 h 09 mindaylight on June 21
Shortest day9 h 12 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation50.6 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 38 °F, low 24 °F 38°24° JanFebruary: average high 41 °F, low 26 °F 41°26° FebMarch: average high 47 °F, low 32 °F 47°32° MarApril: average high 58 °F, low 42 °F 58°42° AprMay: average high 68 °F, low 52 °F 68°52° MayJune: average high 78 °F, low 62 °F 78°62° JunJuly: average high 83 °F, low 68 °F 83°68° JulAugust: average high 82 °F, low 67 °F 82°67° AugSeptember: average high 75 °F, low 60 °F 75°60° SepOctober: average high 64 °F, low 48 °F 64°48° OctNovember: average high 54 °F, low 38 °F 54°38° NovDecember: average high 44 °F, low 30 °F 44°30° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 3.67 in precipitation 3.7 JanFebruary: 3.25 in precipitation 3.3 FebMarch: 4.38 in precipitation 4.4 MarApril: 4.28 in precipitation 4.3 AprMay: 4.35 in precipitation 4.3 MayJune: 4.25 in precipitation 4.3 JunJuly: 4.40 in precipitation 4.4 JulAugust: 4.31 in precipitation 4.3 AugSeptember: 4.79 in precipitation 4.8 SepOctober: 4.79 in precipitation 4.8 OctNovember: 3.70 in precipitation 3.7 NovDecember: 4.48 in precipitation 4.5 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Bridgeport Sikorsky Mem Airport, CT (6 mi away); precipitation: Westport 2.5 Ene, CT (4 mi away). Daylight is calculated from latitude.

ZIP codes in Fairfield

068247a
0 to 5 °F
068257a
0 to 5 °F
068287a
0 to 5 °F

Connecticut planting zones →

Questions about Fairfield

What planting zone is Fairfield, CT?

Fairfield, CT is in USDA hardiness zone 7a on the 2023 map (7a: 0 to 5 °F).

When is the last frost in Fairfield, CT?

The median last spring frost is April 5 and the median first fall frost is November 6 (NOAA 1991–2020 normals, Bridgeport Sikorsky Mem Airport station).

When can I plant a garden in Fairfield, CT?

Cool-season crops like peas and spinach go in around Feb 22 – Mar 15; tomatoes, peppers, beans and squash after about Apr 12, once frost risk has passed.

What kind of onions grow in Fairfield, CT?

Long-day onions: the longest day is 15 h 09 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

How much rain and snow does Fairfield, CT get?

About 50.6 inches of precipitation a year (NOAA 1991–2020 normals).