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

Planting zone for 06249 — Lebanon, CT

ZIP code 06249 (Lebanon, Southeastern Connecticut County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is April 28 and the first fall frost October 13.

Where ZIP 06249 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 28
First frostOct 13
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 Lebanon, 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 Lebanon, CT

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 28median — 50% chance of a later frost
Safe for tender plantsMay 11only 10% chance of frost after
First fall frostOctober 13median — 10% chance by Oct 2
Growing season167 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 14 and returns around October 25.

From the NOAA station Willimantic Windham Airport, CT — 8 miles away, elevation 246 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 06249

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 17 – Mar 31
SpinachSow outdoors · Mar 17 – Apr 7
Broccoli, cabbageStart indoors · Feb 17 – Mar 3
Broccoli, cabbageTransplant · Apr 7 – Apr 21
Onion setsPlant outdoors · Mar 31 – Apr 14
PotatoesPlant outdoors · Apr 7 – Apr 21
LettuceSow outdoors · Mar 31 – Apr 14
Carrots, beetsSow outdoors · Apr 7 – Apr 21
TomatoesStart indoors · Mar 3 – Mar 17
TomatoesTransplant · May 5 – May 19
Peppers, eggplantStart indoors · Feb 17 – Mar 3
Peppers, eggplantTransplant · May 12 – May 26
BeansSow outdoors · May 5 – May 19
Sweet cornSow outdoors · May 5 – May 19
Cucumbers, squashSow outdoors · May 5 – May 19
Fall lettuce, spinachSow outdoors · Aug 18 – Sep 1
GarlicPlant cloves · Sep 29 – Nov 3
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 28) and first fall frost (Oct 13) 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 06249 came on Apr 3 — 5 days earlier than the 1991–2020 average (Apr 8).

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 Lebanon, CT

The soil mapped at the center of ZIP 06249 is Ridgebury — moderately decomposed plant material, poorly drained.

TextureModerately decomposed plant materialtop layer
DrainagePoorly drainedconsider raised beds
Organic matter95%high
Hydrologic groupDwater soaks in very slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Ridgebury, Leicester, and Whitman soils, 0 to 8 percent slopes, extremely 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 06249; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Lebanon, CT

Summer high83 °Faverage high, July
Winter low18 °Faverage low, January
Hot days11days a year at 90 °F or more
Freezing nights135nights a year at 32 °F or less
Growing degree days2,758base 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)
Precipitation43.3 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 36 °F, low 18 °F 36°18° JanFebruary: average high 39 °F, low 19 °F 39°19° FebMarch: average high 47 °F, low 27 °F 47°27° MarApril: average high 59 °F, low 37 °F 59°37° AprMay: average high 70 °F, low 47 °F 70°47° MayJune: average high 78 °F, low 56 °F 78°56° JunJuly: average high 83 °F, low 62 °F 83°62° JulAugust: average high 81 °F, low 60 °F 81°60° AugSeptember: average high 74 °F, low 52 °F 74°52° SepOctober: average high 63 °F, low 41 °F 63°41° OctNovember: average high 52 °F, low 31 °F 52°31° NovDecember: average high 41 °F, low 24 °F 41°24° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 3.20 in precipitation 3.2 JanFebruary: 2.66 in precipitation 2.7 FebMarch: 3.95 in precipitation 4.0 MarApril: 3.97 in precipitation 4.0 AprMay: 3.40 in precipitation 3.4 MayJune: 3.87 in precipitation 3.9 JunJuly: 2.66 in precipitation 2.7 JulAugust: 4.37 in precipitation 4.4 AugSeptember: 4.11 in precipitation 4.1 SepOctober: 3.83 in precipitation 3.8 OctNovember: 3.55 in precipitation 3.5 NovDecember: 3.68 in precipitation 3.7 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Willimantic Windham Airport, CT (8 mi away); precipitation: Willimantic Windham Airport, CT (8 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6b.

063366b
Gilman, CT · 4 mi
062666b
South Windham, CT · 4 mi
062546b
North Franklin, CT · 5 mi
062376b
Columbia, CT · 5 mi
062266b
Willimantic, CT · 5 mi
062316b
Amston, CT · 7 mi
062806b
Windham, CT · 7 mi
063346b
Bozrah, CT · 7 mi

Connecticut planting zones →

Questions about 06249

What planting zone is ZIP code 06249?

ZIP code 06249 (Lebanon, 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 Lebanon, CT?

The median last spring frost (32 °F) near 06249 is April 28; after May 11 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Willimantic Windham Airport station.

When is the first frost in Lebanon, CT?

The median first fall frost near 06249 is October 13, giving a median frost-free growing season of 167 days.

When should I plant tomatoes in 06249?

Start tomato seeds indoors around Mar 3 – Mar 17 and set transplants outside around May 5 – May 19, one to three weeks after the median last frost.

How much rain and snow does 06249 get?

About 43.3 inches of precipitation a year (NOAA 1991–2020 normals, Willimantic Windham Airport station).

How hot do summers get in Lebanon, CT?

The average high peaks at 83 °F in July, with about 11 days a year at 90 °F or more.

What kind of soil does 06249 have?

The USDA soil survey maps Ridgebury at the center of ZIP 06249: moderately decomposed plant material, poorly drained.

Did spring come early in Lebanon, CT in 2026?

Spring leaf-out near 06249 came on Apr 3 in 2026, 5 days earlier than the 1991–2020 average (Apr 8), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Lebanon, CT?

Long-day onions: the longest day near 06249 is 15 h 12 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 06249 change?

Yes. The 2012 USDA map put 06249 in zone 6a; the 2023 map puts it in zone 6b. The newer map uses 1991–2020 data and more weather stations.