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

Planting zone for 01473 — Westminster, MA

ZIP code 01473 (Westminster, Worcester County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is May 2 and the first fall frost October 13.

Where ZIP 01473 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.

Zone6a−10 to −5 °F
Coldest night−23.3 to −20.6 °C
Last frostMay 2
First frostOct 13
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 Westminster, 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 Westminster, MA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 2median — 50% chance of a later frost
Safe for tender plantsMay 16only 10% chance of frost after
First fall frostOctober 13median — 10% chance by Oct 1
Growing season163 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 18 and returns around October 25.

From the NOAA station Ashburnham, MA — 4 miles away, elevation 1,109 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 01473

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 21 – Apr 4
SpinachSow outdoors · Mar 21 – Apr 11
Broccoli, cabbageStart indoors · Feb 21 – Mar 7
Broccoli, cabbageTransplant · Apr 11 – Apr 25
Onion setsPlant outdoors · Apr 4 – Apr 18
PotatoesPlant outdoors · Apr 11 – Apr 25
LettuceSow outdoors · Apr 4 – Apr 18
Carrots, beetsSow outdoors · Apr 11 – Apr 25
TomatoesStart indoors · Mar 7 – Mar 21
TomatoesTransplant · May 9 – May 23
Peppers, eggplantStart indoors · Feb 21 – Mar 7
Peppers, eggplantTransplant · May 16 – May 30
BeansSow outdoors · May 9 – May 23
Sweet cornSow outdoors · May 9 – May 23
Cucumbers, squashSow outdoors · May 9 – May 23
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 (May 2) 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 01473 came on Apr 12 — 5 days earlier than the 1991–2020 average (Apr 17).

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 Westminster, MA.

Soil in Westminster, MA

The soil mapped at the center of ZIP 01473 is Berkshire — slightly decomposed plant material, well drained.

TextureSlightly decomposed plant materialtop layer
pH3.5strongly acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter85%high
Hydrologic groupBwater soaks in moderately
Farmland classNot prime farmlandUSDA classification

Map unit: Berkshire-Marlow association, 15 to 45 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 01473; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Westminster, MA

Summer high80 °Faverage high, July
Winter low14 °Faverage low, January
Hot days3days a year at 90 °F or more
Freezing nights152nights a year at 32 °F or less
Growing degree days2,244base 50 °F — the season’s usable heat
Longest day15 h 18 mindaylight on June 21
Shortest day9 h 03 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation49.1 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 31 °F, low 14 °F 31°14° JanFebruary: average high 33 °F, low 15 °F 33°15° FebMarch: average high 41 °F, low 23 °F 41°23° MarApril: average high 55 °F, low 34 °F 55°34° AprMay: average high 66 °F, low 44 °F 66°44° MayJune: average high 75 °F, low 54 °F 75°54° JunJuly: average high 80 °F, low 60 °F 80°60° JulAugust: average high 78 °F, low 57 °F 78°57° AugSeptember: average high 71 °F, low 51 °F 71°51° SepOctober: average high 57 °F, low 39 °F 57°39° OctNovember: average high 46 °F, low 31 °F 46°31° NovDecember: average high 35 °F, low 20 °F 35°20° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 3.47 in precipitation 3.5 JanFebruary: 3.13 in precipitation 3.1 FebMarch: 4.04 in precipitation 4.0 MarApril: 4.09 in precipitation 4.1 AprMay: 4.04 in precipitation 4.0 MayJune: 4.41 in precipitation 4.4 JunJuly: 3.74 in precipitation 3.7 JulAugust: 4.59 in precipitation 4.6 AugSeptember: 4.29 in precipitation 4.3 SepOctober: 5.04 in precipitation 5.0 OctNovember: 3.78 in precipitation 3.8 NovDecember: 4.48 in precipitation 4.5 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Ashburnham, MA (4 mi away); precipitation: Westminster 0.6 Wsw, MA (within 1 mile). Daylight is calculated from latitude.

Nearby ZIP codes

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

014416a
Westminster, MA · <1 mi
014405b
Gardner, MA · 5 mi
014206a
Fitchburg, MA · 5 mi
014525b
Hubbardston, MA · 6 mi
014385b
East Templeton, MA · 7 mi
015416a
Princeton, MA · 7 mi
014536a
Leominster, MA · 8 mi
014306a
Ashburnham, MA · 8 mi

All 2 ZIP codes in Westminster → · Massachusetts planting zones →

Questions about 01473

What planting zone is ZIP code 01473?

ZIP code 01473 (Westminster, 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 Westminster, MA?

The median last spring frost (32 °F) near 01473 is May 2; after May 16 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Ashburnham station.

When is the first frost in Westminster, MA?

The median first fall frost near 01473 is October 13, giving a median frost-free growing season of 163 days.

When should I plant tomatoes in 01473?

Start tomato seeds indoors around Mar 7 – Mar 21 and set transplants outside around May 9 – May 23, one to three weeks after the median last frost.

How much rain and snow does 01473 get?

About 49.1 inches of precipitation a year (NOAA 1991–2020 normals, Westminster 0.6 Wsw station).

How hot do summers get in Westminster, MA?

The average high peaks at 80 °F in July, with about 3 days a year at 90 °F or more.

What kind of soil does 01473 have?

The USDA soil survey maps Berkshire at the center of ZIP 01473: slightly decomposed plant material, well drained, pH about 3.5 (strongly acidic).

Did spring come early in Westminster, MA in 2026?

Spring leaf-out near 01473 came on Apr 12 in 2026, 5 days earlier than the 1991–2020 average (Apr 17), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Westminster, MA?

Long-day onions: the longest day near 01473 is 15 h 18 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 01473 change?

Yes. The 2012 USDA map put 01473 in zone 5b; the 2023 map puts it in zone 6a. The newer map uses 1991–2020 data and more weather stations.