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

Planting zone for 21540 — Luke, MD

ZIP code 21540 (Luke, Allegany County) is in USDA zone 7a: the coldest winter night averages 0 to 5 °F. The median last spring frost is April 29 and the first fall frost October 20.

Where ZIP 21540 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.

Zone7a0 to 5 °F
Coldest night−17.8 to −15 °C
Last frostApr 29
First frostOct 20
2012 zone6b

Was 6b 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 7a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Luke, MD…

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 Luke, MD

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 29median — 50% chance of a later frost
Safe for tender plantsMay 15only 10% chance of frost after
First fall frostOctober 20median — 10% chance by Oct 4
Growing season174 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 12 and returns around November 1.

From the NOAA station Savage Rvr Dam, MD — 5 miles away, elevation 1,496 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 21540

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 18 – Apr 1
SpinachSow outdoors · Mar 18 – Apr 8
Broccoli, cabbageStart indoors · Feb 18 – Mar 4
Broccoli, cabbageTransplant · Apr 8 – Apr 22
Onion setsPlant outdoors · Apr 1 – Apr 15
PotatoesPlant outdoors · Apr 8 – Apr 22
LettuceSow outdoors · Apr 1 – Apr 15
Carrots, beetsSow outdoors · Apr 8 – Apr 22
TomatoesStart indoors · Mar 4 – Mar 18
TomatoesTransplant · May 6 – May 20
Peppers, eggplantStart indoors · Feb 18 – Mar 4
Peppers, eggplantTransplant · May 13 – May 27
BeansSow outdoors · May 6 – May 20
Sweet cornSow outdoors · May 6 – May 20
Cucumbers, squashSow outdoors · May 6 – May 20
Fall lettuce, spinachSow outdoors · Aug 25 – Sep 8
GarlicPlant cloves · Oct 6 – Nov 10
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 29) and first fall frost (Oct 20) 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 21540 came on Mar 16 — 17 days earlier than the 1991–2020 average (Apr 2).

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.

Trees 82

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 126

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 beautyberry6 ft · blooms early summer · medium shade tolerance · to −8 °FAmerican black currant3 ft · blooms early spring · to −46 °FAmerican hazelnut10 ft · blooms spring · medium shade tolerance · to −33 °F

Wildflowers & perennials 203

American bur-reed3 ft · blooms indeterminate · medium shade tolerance · to −33 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °FAmerican lotus3 ft · blooms mid summer · high shade tolerance · to −36 °FAmerican pokeweed7 ft · blooms mid summer · low shade tolerance · to −33 °FAmerican speedwell0.8 ft · blooms mid summer · low shade tolerance · to −38 °FAmerican spongeplant0.5 ft · blooms mid spring · high shade tolerance · to −24 °F

Grasses 175

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 °Fautumn bluegrass1.5 ft · blooms late spring · medium shade tolerance · to −8 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °F

Vines 12

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °FAmerican wisteria50 ft · blooms spring · low shade tolerance · to −3 °Fdevil's darning needles15 ft · blooms mid summer · medium shade tolerance · to −38 °Ffrost grape83 ft · blooms late spring · medium shade tolerance · to −23 °Fgraybark grape50 ft · blooms late spring · medium shade tolerance · to −8 °Fheartleaf peppervine2 ft · blooms late spring · low shade tolerance · to −8 °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 Luke, MD.

Soil in Luke, MD

The soil mapped at the center of ZIP 21540 is Gilpin — silt loam, well drained.

TextureSilt loama good balance for most vegetables
pH4.6strongly acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter2.25%moderate
Hydrologic groupCwater soaks in slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Gilpin very stony-Macove very rubbly complex, 45 to 65 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 21540; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Luke, MD

Summer high81 °Faverage high, July
Winter low20 °Faverage low, January
Hot days6days a year at 90 °F or more
Freezing nights130nights a year at 32 °F or less
Growing degree days2,642base 50 °F — the season’s usable heat
Longest day14 h 58 mindaylight on June 21
Shortest day9 h 23 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation41.4 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 36 °F, low 20 °F 36°20° JanFebruary: average high 39 °F, low 21 °F 39°21° FebMarch: average high 48 °F, low 28 °F 48°28° MarApril: average high 61 °F, low 37 °F 61°37° AprMay: average high 69 °F, low 47 °F 69°47° MayJune: average high 77 °F, low 56 °F 77°56° JunJuly: average high 81 °F, low 60 °F 81°60° 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 41 °F 62°41° OctNovember: average high 50 °F, low 32 °F 50°32° NovDecember: average high 40 °F, low 25 °F 40°25° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 2.99 in precipitation 3.0 JanFebruary: 2.64 in precipitation 2.6 FebMarch: 3.29 in precipitation 3.3 MarApril: 3.66 in precipitation 3.7 AprMay: 4.58 in precipitation 4.6 MayJune: 4.62 in precipitation 4.6 JunJuly: 4.14 in precipitation 4.1 JulAugust: 3.46 in precipitation 3.5 AugSeptember: 3.75 in precipitation 3.8 SepOctober: 2.93 in precipitation 2.9 OctNovember: 2.44 in precipitation 2.4 NovDecember: 2.91 in precipitation 2.9 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Savage Rvr Dam, MD (5 mi away); precipitation: Savage Rvr Dam, MD (5 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

267507a
Piedmont, WV · <1 mi
215236b
Bloomington, MD · 1 mi
215626b
Westernport, MD · 3 mi
215216b
Barton, MD · 5 mi
267267a
Keyser, WV · 7 mi
215616a
Swanton, MD · 7 mi
215577a
Rawlings, MD · 8 mi
215396a
Lonaconing, MD · 8 mi

Maryland planting zones →

Questions about 21540

What planting zone is ZIP code 21540?

ZIP code 21540 (Luke, MD) is in USDA hardiness zone 7a on the 2023 map: the coldest night of an average winter reaches 0 to 5 °F (−17.8 to −15 °C).

When is the last frost in Luke, MD?

The median last spring frost (32 °F) near 21540 is April 29; after May 15 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Savage Rvr Dam station.

When is the first frost in Luke, MD?

The median first fall frost near 21540 is October 20, giving a median frost-free growing season of 174 days.

When should I plant tomatoes in 21540?

Start tomato seeds indoors around Mar 4 – Mar 18 and set transplants outside around May 6 – May 20, one to three weeks after the median last frost.

How much rain and snow does 21540 get?

About 41.4 inches of precipitation a year (NOAA 1991–2020 normals, Savage Rvr Dam station).

How hot do summers get in Luke, MD?

The average high peaks at 81 °F in July, with about 6 days a year at 90 °F or more.

What kind of soil does 21540 have?

The USDA soil survey maps Gilpin at the center of ZIP 21540: silt loam, well drained, pH about 4.6 (strongly acidic).

Did spring come early in Luke, MD in 2026?

Spring leaf-out near 21540 came on Mar 16 in 2026, 17 days earlier than the 1991–2020 average (Apr 2), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Luke, MD?

Intermediate onions: the longest day near 21540 is 14 h 58 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 21540 change?

Yes. The 2012 USDA map put 21540 in zone 6b; the 2023 map puts it in zone 7a. The newer map uses 1991–2020 data and more weather stations.