Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for Westminster, MD

Westminster, MD is in USDA zone 7a across its 2 ZIP codes. The median last spring frost is April 19 and the first fall frost October 25.

Westminster on the zone map

Outlined: its 2 ZIP code areas · 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.

Zone7a0 to 5 °F

ZIP codes2

Last frostApr 19

First frostOct 25

Growing season188 days

7a 2 ZIPs

Frost forecast — next 7 nights

live from the National Weather Service

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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, MD

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostApril 19median — 50% chance of a later frost

Safe for tender plantsMay 8only 10% chance of frost after

First fall frostOctober 25median — 10% chance by Oct 8

Growing season188 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 5 and returns around November 4.

From the NOAA station Millers 4 Ne, MD, elevation 860 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 Westminster

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 8 – Mar 22

SpinachSow outdoors · Mar 8 – Mar 29

Broccoli, cabbageStart indoors · Feb 8 – Feb 22

Broccoli, cabbageTransplant · Mar 29 – Apr 12

Onion setsPlant outdoors · Mar 22 – Apr 5

PotatoesPlant outdoors · Mar 29 – Apr 12

LettuceSow outdoors · Mar 22 – Apr 5

Carrots, beetsSow outdoors · Mar 29 – Apr 12

TomatoesStart indoors · Feb 22 – Mar 8

TomatoesTransplant · Apr 26 – May 10

Peppers, eggplantStart indoors · Feb 8 – Feb 22

Peppers, eggplantTransplant · May 3 – May 17

BeansSow outdoors · Apr 26 – May 10

Sweet cornSow outdoors · Apr 26 – May 10

Cucumbers, squashSow outdoors · Apr 26 – May 10

Fall lettuce, spinachSow outdoors · Aug 30 – Sep 13

GarlicPlant cloves · Oct 11 – Nov 15

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 19) and first fall frost (Oct 25) 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 21158 came on Mar 15 — 9 days earlier than the 1991–2020 average (Mar 24).

average
Mar 242026
Mar 15

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 7a in Maryland

612 plants native to the lower 48 states, recorded in Maryland, and rated by the USDA to survive 0 °F or colder — the bottom of zone 7a. Each links to its USDA PLANTS profile.

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, MD.

Soil in Westminster, MD

The soil mapped at the center of ZIP 21158 is Hatboro — silt loam, poorly drained.

TextureSilt loama good balance for most vegetables

pH5.9moderately acidic; most vegetables like 6.0–7.0

DrainagePoorly drainedconsider raised beds

Organic matter3%moderate

Hydrologic groupB/Dmoderate when drained; wet otherwise

Farmland classNot prime farmlandUSDA classification

Map unit: Hatboro silt loam, 0 to 3 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 21158; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Westminster, MD

Summer high85 °Faverage high, July

Winter low21 °Faverage low, January

Hot days18days a year at 90 °F or more

Freezing nights122nights a year at 32 °F or less

Growing degree days3,289base 50 °F — the season’s usable heat

Longest day14 h 58 mindaylight on June 21

Shortest day9 h 22 mindaylight on December 21

Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully

Precipitation45.4 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Hanover 4 Sw, PA (8 mi away); precipitation: Taneytown 4.1 Ne, MD (5 mi away). Daylight is calculated from latitude.

ZIP codes in Westminster

Maryland planting zones →

Questions about Westminster

What planting zone is Westminster, MD?

Westminster, MD is in USDA hardiness zone 7a on the 2023 map (7a: 0 to 5 °F).

When is the last frost in Westminster, MD?

The median last spring frost is April 19 and the median first fall frost is October 25 (NOAA 1991–2020 normals, Millers 4 Ne station).

When can I plant a garden in Westminster, MD?

Cool-season crops like peas and spinach go in around Mar 8 – Mar 29; tomatoes, peppers, beans and squash after about Apr 26, once frost risk has passed.

What kind of onions grow in Westminster, MD?

Intermediate onions: the longest day is 14 h 58 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

How much rain and snow does Westminster, MD get?

About 45.4 inches of precipitation a year (NOAA 1991–2020 normals).