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

Planting zone for 06232 — Andover, CT

ZIP code 06232 (Andover, Capitol Region County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is April 19 and the first fall frost October 22.

Where ZIP 06232 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 19
First frostOct 22
2012 zone6a

Was 6a on the 2012 map — half a zone warmer now. 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 Andover, 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 Andover, CT

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 19median — 50% chance of a later frost
Safe for tender plantsMay 3only 10% chance of frost after
First fall frostOctober 22median — 10% chance by Oct 6
Growing season186 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 6 and returns around November 4.

From the NOAA station Storrs, CT — 9 miles away, elevation 666 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 06232

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 8 – Mar 22
SpinachSow outdoors · Mar 8 – Mar 29
Broccoli, cabbageStart indoors · Feb 8 – Feb 22
Broccoli, cabbageTransplant · Mar 29 – Apr 12
Onion setsPlant outdoors · Mar 22 – Apr 5
PotatoesPlant outdoors · Mar 29 – Apr 12
LettuceSow outdoors · Mar 22 – Apr 5
Carrots, beetsSow outdoors · Mar 29 – Apr 12
TomatoesStart indoors · Feb 22 – Mar 8
TomatoesTransplant · Apr 26 – May 10
Peppers, eggplantStart indoors · Feb 8 – Feb 22
Peppers, eggplantTransplant · May 3 – May 17
BeansSow outdoors · Apr 26 – May 10
Sweet cornSow outdoors · Apr 26 – May 10
Cucumbers, squashSow outdoors · Apr 26 – May 10
Fall lettuce, spinachSow outdoors · Aug 27 – Sep 10
GarlicPlant cloves · Oct 8 – Nov 12
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 19) and first fall frost (Oct 22) 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 06232 came on Apr 3 — 6 days earlier than the 1991–2020 average (Apr 9).

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).

Soil in Andover, CT

The soil mapped at the center of ZIP 06232 is Catden — muck, very poorly drained.

TextureMucktop layer
DrainageVery poorly drainedconsider raised beds
Organic matter82%high
Hydrologic groupB/Dmoderate when drained; wet otherwise
Farmland classNot prime farmlandUSDA classification

Map unit: Catden and Freetown soils, 0 to 2 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 06232; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Andover, CT

Summer high81 °Faverage high, July
Winter low19 °Faverage low, January
Hot days3days a year at 90 °F or more
Freezing nights123nights a year at 32 °F or less
Growing degree days2,683base 50 °F — the season’s usable heat
Longest day15 h 13 mindaylight on June 21
Shortest day9 h 08 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation49.3 inper year, rain and melted snow
Snowfall39 inper year

Average high and low, by month

10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 35 °F, low 19 °F 35°19° JanFebruary: average high 37 °F, low 20 °F 37°20° FebMarch: average high 45 °F, low 28 °F 45°28° MarApril: average high 57 °F, low 38 °F 57°38° AprMay: average high 68 °F, low 48 °F 68°48° MayJune: average high 76 °F, low 57 °F 76°57° JunJuly: average high 81 °F, low 63 °F 81°63° JulAugust: average high 79 °F, low 61 °F 79°61° AugSeptember: average high 73 °F, low 54 °F 73°54° SepOctober: average high 61 °F, low 43 °F 61°43° OctNovember: average high 50 °F, low 34 °F 50°34° NovDecember: average high 40 °F, low 25 °F 40°25° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″January: 3.65 in precipitation, 8.3 in snowfall 3.6❄8 JanFebruary: 2.99 in precipitation, 14.1 in snowfall 3.0❄14 FebMarch: 4.38 in precipitation, 6.3 in snowfall 4.4❄6 MarApril: 4.23 in precipitation, 1.7 in snowfall 4.2❄2 AprMay: 3.73 in precipitation 3.7 MayJune: 4.52 in precipitation 4.5 JunJuly: 4.01 in precipitation 4.0 JulAugust: 4.30 in precipitation 4.3 AugSeptember: 4.48 in precipitation 4.5 SepOctober: 4.58 in precipitation, 0.3 in snowfall 4.6 OctNovember: 3.90 in precipitation, 1.1 in snowfall 3.9❄1 NovDecember: 4.50 in precipitation, 7.2 in snowfall 4.5❄7 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Storrs, CT (9 mi away); precipitation: Storrs, CT (9 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6b.

062486b
Hebron, CT · 4 mi
062386b
Coventry, CT · 4 mi
060436b
Bolton, CT · 4 mi
062376b
Columbia, CT · 4 mi
062516b
Mansfield Depot, CT · 6 mi
062316b
Amston, CT · 7 mi
064476b
Marlborough, CT · 8 mi
062686b
Storrs Mansfield, CT · 8 mi

Connecticut planting zones →

Questions about 06232

What planting zone is ZIP code 06232?

ZIP code 06232 (Andover, 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 Andover, CT?

The median last spring frost (32 °F) near 06232 is April 19; after May 3 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Storrs station.

When is the first frost in Andover, CT?

The median first fall frost near 06232 is October 22, giving a median frost-free growing season of 186 days.

When should I plant tomatoes in 06232?

Start tomato seeds indoors around Feb 22 – Mar 8 and set transplants outside around Apr 26 – May 10, one to three weeks after the median last frost.

How much rain and snow does 06232 get?

About 49.3 inches of precipitation a year and 39 inches of snowfall (NOAA 1991–2020 normals, Storrs station).

How hot do summers get in Andover, CT?

The average high peaks at 81 °F in July, with about 3 days a year at 90 °F or more.

What kind of soil does 06232 have?

The USDA soil survey maps Catden at the center of ZIP 06232: muck, very poorly drained.

Did spring come early in Andover, CT in 2026?

Spring leaf-out near 06232 came on Apr 3 in 2026, 6 days earlier than the 1991–2020 average (Apr 9), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Andover, CT?

Long-day onions: the longest day near 06232 is 15 h 13 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 06232 change?

Yes. The 2012 USDA map put 06232 in zone 6a; the 2023 map puts it in zone 6b. The newer map uses 1991–2020 data and more weather stations.