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

Planting zone for 20903 — Silver Spring, MD

ZIP code 20903 (Silver Spring, Montgomery County) is in USDA zone 7b: the coldest winter night averages 5 to 10 °F. The median last spring frost is April 10 and the first fall frost November 1.

Where ZIP 20903 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.

Zone7b5 to 10 °F
Coldest night−15 to −12.2 °C
Last frostApr 10
First frostNov 1
2012 zone7a

Was 7a 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 7b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Silver Spring, 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 Silver Spring, MD

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 10median — 50% chance of a later frost
Safe for tender plantsMay 1only 10% chance of frost after
First fall frostNovember 1median — 10% chance by Oct 16
Growing season202 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 29 and returns around November 11.

From the NOAA station Beltsville, MD — 2 miles away, elevation 144 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 20903

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Feb 27 – Mar 13
SpinachSow outdoors · Feb 27 – Mar 20
Broccoli, cabbageStart indoors · Jan 30 – Feb 13
Broccoli, cabbageTransplant · Mar 20 – Apr 3
Onion setsPlant outdoors · Mar 13 – Mar 27
PotatoesPlant outdoors · Mar 20 – Apr 3
LettuceSow outdoors · Mar 13 – Mar 27
Carrots, beetsSow outdoors · Mar 20 – Apr 3
TomatoesStart indoors · Feb 13 – Feb 27
TomatoesTransplant · Apr 17 – May 1
Peppers, eggplantStart indoors · Jan 30 – Feb 13
Peppers, eggplantTransplant · Apr 24 – May 8
BeansSow outdoors · Apr 17 – May 1
Sweet cornSow outdoors · Apr 17 – May 1
Cucumbers, squashSow outdoors · Apr 17 – May 1
Fall lettuce, spinachSow outdoors · Sep 6 – Sep 20
GarlicPlant cloves · Oct 18 – Nov 22
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 10) and first fall frost (Nov 1) 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 20903 came on Mar 11 — 5 days earlier than the 1991–2020 average (Mar 16).

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 7b in Maryland

618 plants native to the lower 48 states, recorded in Maryland, and rated by the USDA to survive 5 °F or colder — the bottom of zone 7b. Each links to its USDA PLANTS profile.

Trees 83

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 127

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 206

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 176

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 Silver Spring, MD.

Soil in Silver Spring, MD

The soil mapped at the center of ZIP 20903 is Gaila — 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 matter1.25%low — add compost
Hydrologic groupBwater soaks in moderately
Farmland classprime farmlandUSDA classification

Map unit: Gaila 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 20903; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Silver Spring, MD

Summer high87 °Faverage high, July
Winter low25 °Faverage low, January
Hot days30days a year at 90 °F or more
Freezing nights95nights a year at 32 °F or less
Growing degree days3,927base 50 °F — the season’s usable heat
Longest day14 h 55 mindaylight on June 21
Shortest day9 h 25 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation48 inper year, rain and melted snow

Average high and low, by month

10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 43 °F, low 25 °F 43°25° JanFebruary: average high 46 °F, low 27 °F 46°27° FebMarch: average high 53 °F, low 34 °F 53°34° MarApril: average high 65 °F, low 44 °F 65°44° AprMay: average high 74 °F, low 54 °F 74°54° MayJune: average high 83 °F, low 63 °F 83°63° JunJuly: average high 87 °F, low 68 °F 87°68° JulAugust: average high 86 °F, low 66 °F 86°66° AugSeptember: average high 79 °F, low 59 °F 79°59° SepOctober: average high 68 °F, low 47 °F 68°47° OctNovember: average high 57 °F, low 37 °F 57°37° NovDecember: average high 47 °F, low 30 °F 47°30° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 3.16 in precipitation 3.2 JanFebruary: 2.72 in precipitation 2.7 FebMarch: 3.86 in precipitation 3.9 MarApril: 3.56 in precipitation 3.6 AprMay: 4.66 in precipitation 4.7 MayJune: 5.22 in precipitation 5.2 JunJuly: 4.62 in precipitation 4.6 JulAugust: 4.16 in precipitation 4.2 AugSeptember: 4.48 in precipitation 4.5 SepOctober: 4.32 in precipitation 4.3 OctNovember: 3.34 in precipitation 3.3 NovDecember: 3.93 in precipitation 3.9 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Beltsville, MD (2 mi away); precipitation: Takoma Park 0.6 Nnw, MD (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 7b.

209937b
Silver Spring, MD · <1 mi
209017b
Silver Spring, MD · 2 mi
207837b
Hyattsville, MD · 2 mi
207877b
Hyattsville, MD · 2 mi
207427b
College Park, MD · 3 mi
209127b
Takoma Park, MD · 3 mi
207407b
College Park, MD · 3 mi
209077b
Silver Spring, MD · 3 mi

All 16 ZIP codes in Silver Spring → · Maryland planting zones →

Questions about 20903

What planting zone is ZIP code 20903?

ZIP code 20903 (Silver Spring, MD) is in USDA hardiness zone 7b on the 2023 map: the coldest night of an average winter reaches 5 to 10 °F (−15 to −12.2 °C).

When is the last frost in Silver Spring, MD?

The median last spring frost (32 °F) near 20903 is April 10; after May 1 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Beltsville station.

When is the first frost in Silver Spring, MD?

The median first fall frost near 20903 is November 1, giving a median frost-free growing season of 202 days.

When should I plant tomatoes in 20903?

Start tomato seeds indoors around Feb 13 – Feb 27 and set transplants outside around Apr 17 – May 1, one to three weeks after the median last frost.

How much rain and snow does 20903 get?

About 48 inches of precipitation a year (NOAA 1991–2020 normals, Takoma Park 0.6 Nnw station).

How hot do summers get in Silver Spring, MD?

The average high peaks at 87 °F in July, with about 30 days a year at 90 °F or more.

What kind of soil does 20903 have?

The USDA soil survey maps Gaila at the center of ZIP 20903: silt loam, well drained, pH about 4.6 (strongly acidic).

Did spring come early in Silver Spring, MD in 2026?

Spring leaf-out near 20903 came on Mar 11 in 2026, 5 days earlier than the 1991–2020 average (Mar 16), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Silver Spring, MD?

Intermediate onions: the longest day near 20903 is 14 h 55 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 20903 change?

Yes. The 2012 USDA map put 20903 in zone 7a; the 2023 map puts it in zone 7b. The newer map uses 1991–2020 data and more weather stations.