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

Planting zone for 02156 — West Medford, MA

ZIP code 02156 (West Medford, Middlesex County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is April 25 and the first fall frost October 17.

Where ZIP 02156 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 25
First frostOct 17
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 West Medford, 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 Medford, MA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 25median — 50% chance of a later frost
Safe for tender plantsMay 8only 10% chance of frost after
First fall frostOctober 17median — 10% chance by Oct 3
Growing season174 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 11 and returns around October 30.

From the NOAA station Reading, MA — 7 miles away, elevation 112 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 02156

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 14 – Mar 28
SpinachSow outdoors · Mar 14 – Apr 4
Broccoli, cabbageStart indoors · Feb 14 – Feb 28
Broccoli, cabbageTransplant · Apr 4 – Apr 18
Onion setsPlant outdoors · Mar 28 – Apr 11
PotatoesPlant outdoors · Apr 4 – Apr 18
LettuceSow outdoors · Mar 28 – Apr 11
Carrots, beetsSow outdoors · Apr 4 – Apr 18
TomatoesStart indoors · Feb 28 – Mar 14
TomatoesTransplant · May 2 – May 16
Peppers, eggplantStart indoors · Feb 14 – Feb 28
Peppers, eggplantTransplant · May 9 – May 23
BeansSow outdoors · May 2 – May 16
Sweet cornSow outdoors · May 2 – May 16
Cucumbers, squashSow outdoors · May 2 – May 16
Fall lettuce, spinachSow outdoors · Aug 22 – Sep 5
GarlicPlant cloves · Oct 3 – Nov 7
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 25) and first fall frost (Oct 17) 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 02156 came on Apr 2 — 4 days earlier than the 1991–2020 average (Apr 6).

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 West Medford, MA

The soil mapped at the center of ZIP 02156 is Merrimac — fine sandy loam, somewhat excessively drained.

TextureFine sandy loamdrains and warms fast; dries out and needs more feeding
pH5.1strongly acidic; most vegetables like 6.0–7.0
DrainageSomewhat excessively drainednatural drainage class
Organic matter4.12%moderate
Hydrologic groupAwater soaks in fast
Farmland classNot prime farmlandUSDA classification

Map unit: Merrimac-Urban land complex, 0 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 02156; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in West Medford, MA

Summer high84 °Faverage high, July
Winter low19 °Faverage low, January
Hot days12days a year at 90 °F or more
Freezing nights134nights a year at 32 °F or less
Growing degree days2,875base 50 °F — the season’s usable heat
Longest day15 h 18 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)
Precipitation48.4 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 38 °F, low 19 °F 38°19° JanFebruary: average high 40 °F, low 20 °F 40°20° FebMarch: average high 48 °F, low 27 °F 48°27° MarApril: average high 60 °F, low 37 °F 60°37° AprMay: average high 70 °F, low 47 °F 70°47° MayJune: average high 78 °F, low 56 °F 78°56° JunJuly: average high 84 °F, low 63 °F 84°63° JulAugust: average high 82 °F, low 61 °F 82°61° AugSeptember: average high 75 °F, low 53 °F 75°53° SepOctober: average high 64 °F, low 42 °F 64°42° OctNovember: average high 53 °F, low 32 °F 53°32° NovDecember: average high 43 °F, low 24 °F 43°24° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 3.78 in precipitation 3.8 JanFebruary: 3.47 in precipitation 3.5 FebMarch: 4.59 in precipitation 4.6 MarApril: 4.20 in precipitation 4.2 AprMay: 3.63 in precipitation 3.6 MayJune: 4.18 in precipitation 4.2 JunJuly: 3.56 in precipitation 3.6 JulAugust: 3.57 in precipitation 3.6 AugSeptember: 3.71 in precipitation 3.7 SepOctober: 4.87 in precipitation 4.9 OctNovember: 3.97 in precipitation 4.0 NovDecember: 4.91 in precipitation 4.9 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Reading, MA (7 mi away); precipitation: Winchester 0.7 Se, MA (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6b.

024746b
Arlington, MA · 1 mi
021556b
Medford, MA · 1 mi
021446b
Somerville, MA · 2 mi
021406b
Cambridge, MA · 2 mi
024766b
Arlington, MA · 2 mi
018906b
Winchester, MA · 2 mi
024756b
Arlington Heights, MA · 2 mi
021386b
Cambridge, MA · 3 mi

Massachusetts planting zones →

Questions about 02156

What planting zone is ZIP code 02156?

ZIP code 02156 (West Medford, 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 West Medford, MA?

The median last spring frost (32 °F) near 02156 is April 25; after May 8 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Reading station.

When is the first frost in West Medford, MA?

The median first fall frost near 02156 is October 17, giving a median frost-free growing season of 174 days.

When should I plant tomatoes in 02156?

Start tomato seeds indoors around Feb 28 – Mar 14 and set transplants outside around May 2 – May 16, one to three weeks after the median last frost.

How much rain and snow does 02156 get?

About 48.4 inches of precipitation a year (NOAA 1991–2020 normals, Winchester 0.7 Se station).

How hot do summers get in West Medford, MA?

The average high peaks at 84 °F in July, with about 12 days a year at 90 °F or more.

What kind of soil does 02156 have?

The USDA soil survey maps Merrimac at the center of ZIP 02156: fine sandy loam, somewhat excessively drained, pH about 5.1 (strongly acidic).

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

Spring leaf-out near 02156 came on Apr 2 in 2026, 4 days earlier than the 1991–2020 average (Apr 6), according to the USA National Phenology Network Spring Index.

What kind of onions grow in West Medford, MA?

Long-day onions: the longest day near 02156 is 15 h 18 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).