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

Planting zone for 21520 — Accident, MD

ZIP code 21520 (Accident, Garrett County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is May 9 and the first fall frost October 11.

Where ZIP 21520 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 9

First frostOct 11

2012 zone6a

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 6a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Accident, 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 Accident, MD

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 9median — 50% chance of a later frost

Safe for tender plantsMay 30only 10% chance of frost after

First fall frostOctober 11median — 10% chance by Sep 27

Growing season155 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 25 and returns around October 24.

From the NOAA station Sines Deep Creek, MD — 10 miles away, elevation 2,041 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 21520

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 28 – Apr 11

SpinachSow outdoors · Mar 28 – Apr 18

Broccoli, cabbageStart indoors · Feb 28 – Mar 14

Broccoli, cabbageTransplant · Apr 18 – May 2

Onion setsPlant outdoors · Apr 11 – Apr 25

PotatoesPlant outdoors · Apr 18 – May 2

LettuceSow outdoors · Apr 11 – Apr 25

Carrots, beetsSow outdoors · Apr 18 – May 2

TomatoesStart indoors · Mar 14 – Mar 28

TomatoesTransplant · May 16 – May 30

Peppers, eggplantStart indoors · Feb 28 – Mar 14

Peppers, eggplantTransplant · May 23 – Jun 6

BeansSow outdoors · May 16 – May 30

Sweet cornSow outdoors · May 16 – May 30

Cucumbers, squashSow outdoors · May 16 – May 30

Fall lettuce, spinachSow outdoors · Aug 16 – Aug 30

GarlicPlant cloves · Sep 27 – Nov 1

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 9) and first fall frost (Oct 11) 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 21520 came on Mar 12 — 25 days earlier than the 1991–2020 average (Apr 6).

average
Apr 62026
Mar 12

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 Maryland

571 plants native to the lower 48 states, recorded in Maryland, and rated by the USDA to survive −10 °F or colder — the bottom of zone 6a. 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 Accident, MD.

Soil in Accident, MD

The soil mapped at the center of ZIP 21520 is Albrights — silt loam, moderately well drained.

TextureSilt loama good balance for most vegetables

pH5.7moderately acidic; most vegetables like 6.0–7.0

DrainageModerately well drainednatural drainage class

Organic matter2.5%moderate

Hydrologic groupC/Dslow when drained; wet otherwise

Farmland classFarmland of statewide importanceUSDA classification

Map unit: Albrights silt loam, 3 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 21520; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Accident, MD

Summer high79 °Faverage high, July

Winter low17 °Faverage low, January

Hot days0days a year at 90 °F or more

Freezing nights160nights a year at 32 °F or less

Growing degree days2,115base 50 °F — the season’s usable heat

Longest day14 h 59 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

Precipitation52.5 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: Sines Deep Creek, MD (10 mi away); precipitation: Mc Henry 4.8 Sse, MD (11 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6a.

215316a

Friendsville, MD · 6 mi

215416a

Mc Henry, MD · 8 mi

215366a

Grantsville, MD · 8 mi

154116a

Addison, PA · 8 mi

155406a

Fort Hill, PA · 12 mi

215616a

Swanton, MD · 12 mi

154596a

Markleysburg, PA · 12 mi

154856a

Ursina, PA · 13 mi

Maryland planting zones →

Questions about 21520

What planting zone is ZIP code 21520?

ZIP code 21520 (Accident, MD) 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 Accident, MD?

The median last spring frost (32 °F) near 21520 is May 9; after May 30 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Sines Deep Creek station.

When is the first frost in Accident, MD?

The median first fall frost near 21520 is October 11, giving a median frost-free growing season of 155 days.

When should I plant tomatoes in 21520?

Start tomato seeds indoors around Mar 14 – Mar 28 and set transplants outside around May 16 – May 30, one to three weeks after the median last frost.

How much rain and snow does 21520 get?

About 52.5 inches of precipitation a year (NOAA 1991–2020 normals, Mc Henry 4.8 Sse station).

How hot do summers get in Accident, MD?

The average high peaks at 79 °F in July, with about 0 days a year at 90 °F or more.

What kind of soil does 21520 have?

The USDA soil survey maps Albrights at the center of ZIP 21520: silt loam, moderately well drained, pH about 5.7 (moderately acidic).

Did spring come early in Accident, MD in 2026?

Spring leaf-out near 21520 came on Mar 12 in 2026, 25 days earlier than the 1991–2020 average (Apr 6), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Accident, MD?

Intermediate onions: the longest day near 21520 is 14 h 59 min, so day-neutral types bulb best; long-day varieties may not bulb fully.