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

Planting zone for 02454 — Waltham, MA

ZIP code 02454 (Waltham, Middlesex County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is April 26 and the first fall frost October 12.

Where ZIP 02454 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.

Zone6b−5 to 0 °F
Coldest night−20.6 to −17.8 °C
Last frostApr 26
First frostOct 12
2012 zone6b

Same zone as on the 2012 map. 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 Waltham, 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 Waltham, MA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 26median — 50% chance of a later frost
Safe for tender plantsMay 9only 10% chance of frost after
First fall frostOctober 12median — 10% chance by Oct 1
Growing season169 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 13 and returns around October 24.

From the NOAA station Natick, MA — 7 miles away, elevation 180 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 02454

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 15 – Mar 29
SpinachSow outdoors · Mar 15 – Apr 5
Broccoli, cabbageStart indoors · Feb 15 – Mar 1
Broccoli, cabbageTransplant · Apr 5 – Apr 19
Onion setsPlant outdoors · Mar 29 – Apr 12
PotatoesPlant outdoors · Apr 5 – Apr 19
LettuceSow outdoors · Mar 29 – Apr 12
Carrots, beetsSow outdoors · Apr 5 – Apr 19
TomatoesStart indoors · Mar 1 – Mar 15
TomatoesTransplant · May 3 – May 17
Peppers, eggplantStart indoors · Feb 15 – Mar 1
Peppers, eggplantTransplant · May 10 – May 24
BeansSow outdoors · May 3 – May 17
Sweet cornSow outdoors · May 3 – May 17
Cucumbers, squashSow outdoors · May 3 – May 17
Fall lettuce, spinachSow outdoors · Aug 17 – Aug 31
GarlicPlant cloves · Sep 28 – Nov 2
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 26) and first fall frost (Oct 12) 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 02454 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).

Native plants for zone 6b in Massachusetts

548 plants native to the lower 48 states, recorded in Massachusetts, and rated by the USDA to survive −5 °F or colder — the bottom of zone 6b. 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 188

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 159

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 °FAtlantic mannagrass3 ft · blooms summer · low shade tolerance · to −8 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °FBailey's sedge2.1 ft · blooms late spring · low shade tolerance · to −33 °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 Waltham, MA.

Soil in Waltham, MA

The soil mapped at the center of ZIP 02454 is Hinckley — moderately decomposed plant material, excessively drained.

TextureModerately decomposed plant materialtop layer
DrainageExcessively drainednatural drainage class
Organic matter95%high
Hydrologic groupAwater soaks in fast
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Hinckley loamy sand, 8 to 15 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 02454; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Waltham, MA

Summer high82 °Faverage high, July
Winter low18 °Faverage low, January
Hot days7days a year at 90 °F or more
Freezing nights143nights a year at 32 °F or less
Growing degree days2,568base 50 °F — the season’s usable heat
Longest day15 h 17 mindaylight on June 21
Shortest day9 h 04 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

Average high and low, by month

10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 35 °F, low 18 °F 35°18° JanFebruary: average high 38 °F, low 18 °F 38°18° FebMarch: average high 46 °F, low 25 °F 46°25° MarApril: average high 58 °F, low 35 °F 58°35° AprMay: average high 68 °F, low 46 °F 68°46° MayJune: average high 77 °F, low 56 °F 77°56° JunJuly: average high 82 °F, low 62 °F 82°62° JulAugust: average high 80 °F, low 59 °F 80°59° AugSeptember: average high 73 °F, low 52 °F 73°52° SepOctober: average high 62 °F, low 40 °F 62°40° OctNovember: average high 51 °F, low 31 °F 51°31° NovDecember: average high 41 °F, low 23 °F 41°23° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 3.72 in precipitation 3.7 JanFebruary: 3.74 in precipitation 3.7 FebMarch: 4.52 in precipitation 4.5 MarApril: 4.37 in precipitation 4.4 AprMay: 3.66 in precipitation 3.7 MayJune: 4.38 in precipitation 4.4 JunJuly: 3.46 in precipitation 3.5 JulAugust: 3.72 in precipitation 3.7 AugSeptember: 3.92 in precipitation 3.9 SepOctober: 4.78 in precipitation 4.8 OctNovember: 4.05 in precipitation 4.0 NovDecember: 4.97 in precipitation 5.0 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Natick, MA (7 mi away); precipitation: Cambridge 0.9 Nnw, MA (7 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6b.

024666b
Auburndale, MA · <1 mi
024536b
Waltham, MA · <1 mi
024656b
West Newton, MA · 1 mi
024626b
Newton Lower Falls, MA · 2 mi
024686b
Waban, MA · 2 mi
024606b
Newtonville, MA · 2 mi
024556b
North Waltham, MA · 2 mi
024956b
Nonantum, MA · 2 mi

All 4 ZIP codes in Waltham → · Massachusetts planting zones →

Questions about 02454

What planting zone is ZIP code 02454?

ZIP code 02454 (Waltham, MA) 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 Waltham, MA?

The median last spring frost (32 °F) near 02454 is April 26; after May 9 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Natick station.

When is the first frost in Waltham, MA?

The median first fall frost near 02454 is October 12, giving a median frost-free growing season of 169 days.

When should I plant tomatoes in 02454?

Start tomato seeds indoors around Mar 1 – Mar 15 and set transplants outside around May 3 – May 17, one to three weeks after the median last frost.

How much rain and snow does 02454 get?

About 49.3 inches of precipitation a year (NOAA 1991–2020 normals, Cambridge 0.9 Nnw station).

How hot do summers get in Waltham, MA?

The average high peaks at 82 °F in July, with about 7 days a year at 90 °F or more.

What kind of soil does 02454 have?

The USDA soil survey maps Hinckley at the center of ZIP 02454: moderately decomposed plant material, excessively drained.

Did spring come early in Waltham, MA in 2026?

Spring leaf-out near 02454 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 Waltham, MA?

Long-day onions: the longest day near 02454 is 15 h 17 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).