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

Planting zone for 05840 — Granby, VT

ZIP code 05840 (Granby, Essex County) is in USDA zone 4b: the coldest winter night averages −25 to −20 °F. The median last spring frost is May 30 and the first fall frost September 16.

Where ZIP 05840 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.

Zone4b−25 to −20 °F
Coldest night−31.7 to −28.9 °C
Last frostMay 30
First frostSep 16
2012 zone4a

Was 4a 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 4b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Granby, VT…

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 Granby, VT

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 30median — 50% chance of a later frost
Safe for tender plantsJune 11only 10% chance of frost after
First fall frostSeptember 16median — 10% chance by Sep 5
Growing season109 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 17 and returns around September 29.

From the NOAA station E Haven, VT — 7 miles away, elevation 1,001 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 05840

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Apr 18 – May 2
SpinachSow outdoors · Apr 18 – May 9
Broccoli, cabbageStart indoors · Mar 21 – Apr 4
Broccoli, cabbageTransplant · May 9 – May 23
Onion setsPlant outdoors · May 2 – May 16
PotatoesPlant outdoors · May 9 – May 23
LettuceSow outdoors · May 2 – May 16
Carrots, beetsSow outdoors · May 9 – May 23
TomatoesStart indoors · Apr 4 – Apr 18
TomatoesTransplant · Jun 6 – Jun 20
Peppers, eggplantStart indoors · Mar 21 – Apr 4
Peppers, eggplantTransplant · Jun 13 – Jun 27
BeansSow outdoors · Jun 6 – Jun 20
Sweet cornSow outdoors · Jun 6 – Jun 20
Cucumbers, squashSow outdoors · Jun 6 – Jun 20
Fall lettuce, spinachSow outdoors · Jul 22 – Aug 5
GarlicPlant cloves · Sep 2 – Oct 7
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 30) and first fall frost (Sep 16) 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 05840 came on Apr 26 — about the same time as the 1991–2020 average (Apr 27).

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 4b in Vermont

432 plants native to the lower 48 states, recorded in Vermont, and rated by the USDA to survive −25 °F or colder — the bottom of zone 4b. Each links to its USDA PLANTS profile.

Trees 49

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 83

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 hornbeam30 ft · blooms mid spring · low shade tolerance · to −34 °F

Wildflowers & perennials 151

alpine bistort1 ft · blooms mid spring · high shade tolerance · to −38 °Falpine sweetvetch2 ft · blooms early summer · high shade tolerance · to −62 °FAmerican bur-reed3 ft · blooms indeterminate · medium shade tolerance · to −33 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °FAmerican pokeweed7 ft · blooms mid summer · low shade tolerance · to −33 °FAmerican speedwell0.8 ft · blooms mid summer · low shade tolerance · to −38 °F

Grasses 133

American beachgrass2.5 ft · blooms spring · high shade tolerance · to −28 °Farctic brome3 ft · blooms early summer · low shade tolerance · to −33 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °FBailey's sedge2.1 ft · blooms late spring · low shade tolerance · to −33 °FBebb's sedge3 ft · blooms late spring · low shade tolerance · to −38 °FBicknell's sedge3 ft · blooms late spring · low shade tolerance · to −38 °F

Vines 5

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °Fdevil's darning needles15 ft · blooms mid summer · medium shade tolerance · to −38 °Friverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °Ftrumpet honeysuckle16 ft · blooms late summer · low shade tolerance · to −33 °FVirginia creeper1 ft · blooms late spring · medium shade tolerance · to −28 °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 Granby, VT.

Soil in Granby, VT

The soil mapped at the center of ZIP 05840 is Cabot — slightly decomposed plant material, poorly drained.

TextureSlightly decomposed plant materialtop layer
pH4.3strongly acidic; most vegetables like 6.0–7.0
DrainagePoorly drainedconsider raised beds
Organic matter85%high
Hydrologic groupDwater soaks in very slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Cabot-Colonel complex, 8 to 15 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 05840; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Granby, VT

Summer high78 °Faverage high, July
Winter low−1 °Faverage low, January
Hot days3days a year at 90 °F or more
Freezing nights204nights a year at 32 °F or less
Growing degree days1,518base 50 °F — the season’s usable heat
Longest day15 h 34 mindaylight on June 21
Shortest day8 h 49 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation45 inper year, rain and melted snow

Average high and low, by month

−10°0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 24 °F, low -1 °F 24°−1° JanFebruary: average high 28 °F, low 0 °F 28°0° FebMarch: average high 37 °F, low 11 °F 37°11° MarApril: average high 51 °F, low 25 °F 51°25° AprMay: average high 64 °F, low 37 °F 64°37° MayJune: average high 73 °F, low 46 °F 73°46° JunJuly: average high 78 °F, low 51 °F 78°51° JulAugust: average high 77 °F, low 50 °F 77°50° AugSeptember: average high 69 °F, low 41 °F 69°41° SepOctober: average high 55 °F, low 32 °F 55°32° OctNovember: average high 41 °F, low 21 °F 41°21° NovDecember: average high 30 °F, low 10 °F 30°10° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 2.89 in precipitation 2.9 JanFebruary: 2.63 in precipitation 2.6 FebMarch: 2.87 in precipitation 2.9 MarApril: 3.70 in precipitation 3.7 AprMay: 4.31 in precipitation 4.3 MayJune: 4.33 in precipitation 4.3 JunJuly: 4.63 in precipitation 4.6 JulAugust: 4.17 in precipitation 4.2 AugSeptember: 3.73 in precipitation 3.7 SepOctober: 4.35 in precipitation 4.3 OctNovember: 3.60 in precipitation 3.6 NovDecember: 3.74 in precipitation 3.7 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: E Haven, VT (7 mi away); precipitation: Lunenburg 2.3 Nnw, VT (7 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

058584b
North Concord, VT · 5 mi
058374b
East Haven, VT · 5 mi
058324b
East Burke, VT · 7 mi
059054a
Guildhall, VT · 8 mi
059064b
Lunenburg, VT · 8 mi
058714b
West Burke, VT · 12 mi
058244b
Concord, VT · 12 mi
058494b
Lyndon, VT · 12 mi

Vermont planting zones →

Questions about 05840

What planting zone is ZIP code 05840?

ZIP code 05840 (Granby, VT) is in USDA hardiness zone 4b on the 2023 map: the coldest night of an average winter reaches −25 to −20 °F (−31.7 to −28.9 °C).

When is the last frost in Granby, VT?

The median last spring frost (32 °F) near 05840 is May 30; after June 11 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, E Haven station.

When is the first frost in Granby, VT?

The median first fall frost near 05840 is September 16, giving a median frost-free growing season of 109 days.

When should I plant tomatoes in 05840?

Start tomato seeds indoors around Apr 4 – Apr 18 and set transplants outside around Jun 6 – Jun 20, one to three weeks after the median last frost.

How much rain and snow does 05840 get?

About 45 inches of precipitation a year (NOAA 1991–2020 normals, Lunenburg 2.3 Nnw station).

How hot do summers get in Granby, VT?

The average high peaks at 78 °F in July, with about 3 days a year at 90 °F or more.

What kind of soil does 05840 have?

The USDA soil survey maps Cabot at the center of ZIP 05840: slightly decomposed plant material, poorly drained, pH about 4.3 (strongly acidic).

Did spring come early in Granby, VT in 2026?

Spring leaf-out near 05840 came on Apr 26 in 2026, about the same as the 1991–2020 average (Apr 27), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Granby, VT?

Long-day onions: the longest day near 05840 is 15 h 34 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 05840 change?

Yes. The 2012 USDA map put 05840 in zone 4a; the 2023 map puts it in zone 4b. The newer map uses 1991–2020 data and more weather stations.