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

Planting zone for 01586 — West Millbury, MA

ZIP code 01586 (West Millbury, Worcester County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is May 1 and the first fall frost October 10.

Where ZIP 01586 is

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.

Zone6a−10 to −5 °F
Coldest night−23.3 to −20.6 °C
Last frostMay 1
First frostOct 10
2012 zone5b

Was 5b 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 6a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for West Millbury, MA…

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 West Millbury, MA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 1median — 50% chance of a later frost
Safe for tender plantsMay 13only 10% chance of frost after
First fall frostOctober 10median — 10% chance by Sep 28
Growing season162 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 19 and returns around October 22.

From the NOAA station Buffumville Lake, MA — 7 miles away, elevation 522 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 01586

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 20 – Apr 3
SpinachSow outdoors · Mar 20 – Apr 10
Broccoli, cabbageStart indoors · Feb 20 – Mar 6
Broccoli, cabbageTransplant · Apr 10 – Apr 24
Onion setsPlant outdoors · Apr 3 – Apr 17
PotatoesPlant outdoors · Apr 10 – Apr 24
LettuceSow outdoors · Apr 3 – Apr 17
Carrots, beetsSow outdoors · Apr 10 – Apr 24
TomatoesStart indoors · Mar 6 – Mar 20
TomatoesTransplant · May 8 – May 22
Peppers, eggplantStart indoors · Feb 20 – Mar 6
Peppers, eggplantTransplant · May 15 – May 29
BeansSow outdoors · May 8 – May 22
Sweet cornSow outdoors · May 8 – May 22
Cucumbers, squashSow outdoors · May 8 – May 22
Fall lettuce, spinachSow outdoors · Aug 15 – Aug 29
GarlicPlant cloves · Sep 26 – Oct 31
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 1) and first fall frost (Oct 10) 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 01586 came on Apr 8 — 4 days earlier than the 1991–2020 average (Apr 12).

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 6a in Massachusetts

544 plants native to the lower 48 states, recorded in Massachusetts, and rated by the USDA to survive −10 °F or colder — the bottom of zone 6a. Each links to its USDA PLANTS profile.

Trees 66

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 109

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 186

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 °FAmerican cupscale3 ft · blooms early summer · high shade tolerance · to −18 °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 °Fbeaked spikerush3 ft · blooms late spring · high shade tolerance · to −28 °F

Vines 8

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °Fdevil's darning needles15 ft · blooms mid summer · medium shade tolerance · to −38 °Ffrost grape83 ft · blooms late spring · medium shade tolerance · to −23 °Friverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °Fsummer grape30 ft · blooms late spring · low shade tolerance · to −23 °Ftrumpet creeper2 ft · blooms summer · high shade tolerance · to −13 °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 West Millbury, MA.

Soil in West Millbury, MA

The soil mapped at the center of ZIP 01586 is Paxton — fine sandy loam, well drained.

TextureFine sandy loamdrains and warms fast; dries out and needs more feeding
pH5.5moderately acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter5.09%high
Hydrologic groupCwater soaks in slowly
Farmland classprime farmlandUSDA classification

Map unit: Paxton fine sandy loam, 3 to 8 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 01586; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in West Millbury, MA

Summer high83 °Faverage high, July
Winter low15 °Faverage low, January
Hot days8days a year at 90 °F or more
Freezing nights153nights a year at 32 °F or less
Growing degree days2,532base 50 °F — the season’s usable heat
Longest day15 h 16 mindaylight on June 21
Shortest day9 h 06 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation50.1 inper year, rain and melted snow

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 34 °F, low 15 °F 34°15° JanFebruary: average high 37 °F, low 15 °F 37°15° FebMarch: average high 45 °F, low 24 °F 45°24° MarApril: average high 57 °F, low 34 °F 57°34° AprMay: average high 69 °F, low 45 °F 69°45° MayJune: average high 77 °F, low 55 °F 77°55° JunJuly: average high 83 °F, low 60 °F 83°60° JulAugust: average high 81 °F, low 59 °F 81°59° AugSeptember: average high 74 °F, low 51 °F 74°51° SepOctober: average high 61 °F, low 39 °F 61°39° OctNovember: average high 50 °F, low 30 °F 50°30° NovDecember: average high 39 °F, low 21 °F 39°21° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 3.83 in precipitation 3.8 JanFebruary: 3.22 in precipitation 3.2 FebMarch: 4.45 in precipitation 4.5 MarApril: 4.40 in precipitation 4.4 AprMay: 3.59 in precipitation 3.6 MayJune: 4.21 in precipitation 4.2 JunJuly: 4.05 in precipitation 4.0 JulAugust: 4.24 in precipitation 4.2 AugSeptember: 4.18 in precipitation 4.2 SepOctober: 4.98 in precipitation 5.0 OctNovember: 4.26 in precipitation 4.3 NovDecember: 4.67 in precipitation 4.7 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Buffumville Lake, MA (7 mi away); precipitation: Auburn 2.6 Sw, MA (3 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

015276a
Millbury, MA · 2 mi
015016a
Auburn, MA · 3 mi
015906b
Sutton, MA · 4 mi
016076a
Worcester, MA · 4 mi
015376a
North Oxford, MA · 5 mi
015406b
Oxford, MA · 5 mi
016106a
Worcester, MA · 5 mi
016036a
Worcester, MA · 5 mi

Massachusetts planting zones →

Questions about 01586

What planting zone is ZIP code 01586?

ZIP code 01586 (West Millbury, MA) is in USDA hardiness zone 6a on the 2023 map: the coldest night of an average winter reaches −10 to −5 °F (−23.3 to −20.6 °C).

When is the last frost in West Millbury, MA?

The median last spring frost (32 °F) near 01586 is May 1; after May 13 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Buffumville Lake station.

When is the first frost in West Millbury, MA?

The median first fall frost near 01586 is October 10, giving a median frost-free growing season of 162 days.

When should I plant tomatoes in 01586?

Start tomato seeds indoors around Mar 6 – Mar 20 and set transplants outside around May 8 – May 22, one to three weeks after the median last frost.

How much rain and snow does 01586 get?

About 50.1 inches of precipitation a year (NOAA 1991–2020 normals, Auburn 2.6 Sw station).

How hot do summers get in West Millbury, MA?

The average high peaks at 83 °F in July, with about 8 days a year at 90 °F or more.

What kind of soil does 01586 have?

The USDA soil survey maps Paxton at the center of ZIP 01586: fine sandy loam, well drained, pH about 5.5 (moderately acidic).

Did spring come early in West Millbury, MA in 2026?

Spring leaf-out near 01586 came on Apr 8 in 2026, 4 days earlier than the 1991–2020 average (Apr 12), according to the USA National Phenology Network Spring Index.

What kind of onions grow in West Millbury, MA?

Long-day onions: the longest day near 01586 is 15 h 16 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 01586 change?

Yes. The 2012 USDA map put 01586 in zone 5b; the 2023 map puts it in zone 6a. The newer map uses 1991–2020 data and more weather stations.