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

Planting zone for 20810 — Bethesda, MD

ZIP code 20810 (Bethesda, Montgomery County) is in USDA zone 7b: the coldest winter night averages 5 to 10 °F. The median last spring frost is April 9 and the first fall frost October 31.

Where ZIP 20810 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.

Zone7b5 to 10 °F
Coldest night−15 to −12.2 °C
Last frostApr 9
First frostOct 31
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 Bethesda, 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 Bethesda, MD

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 9median — 50% chance of a later frost
Safe for tender plantsApril 26only 10% chance of frost after
First fall frostOctober 31median — 10% chance by Oct 16
Growing season202 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 30 and returns around November 9.

From the NOAA station Dalecarlia Rsvr, MD — 3 miles away, elevation 151 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 20810

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Feb 26 – Mar 12
SpinachSow outdoors · Feb 26 – Mar 19
Broccoli, cabbageStart indoors · Jan 29 – Feb 12
Broccoli, cabbageTransplant · Mar 19 – Apr 2
Onion setsPlant outdoors · Mar 12 – Mar 26
PotatoesPlant outdoors · Mar 19 – Apr 2
LettuceSow outdoors · Mar 12 – Mar 26
Carrots, beetsSow outdoors · Mar 19 – Apr 2
TomatoesStart indoors · Feb 12 – Feb 26
TomatoesTransplant · Apr 16 – Apr 30
Peppers, eggplantStart indoors · Jan 29 – Feb 12
Peppers, eggplantTransplant · Apr 23 – May 7
BeansSow outdoors · Apr 16 – Apr 30
Sweet cornSow outdoors · Apr 16 – Apr 30
Cucumbers, squashSow outdoors · Apr 16 – Apr 30
Fall lettuce, spinachSow outdoors · Sep 5 – Sep 19
GarlicPlant cloves · Oct 17 – Nov 21
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 9) and first fall frost (Oct 31) 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 20810 came on Mar 10 — 6 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 Bethesda, MD.

Soil in Bethesda, MD

The soil mapped at the center of ZIP 20810 is Udorthents — loam, well drained. Much of the area is built over (urban land); this is the natural soil underneath.

TextureLoama good balance for most vegetables
pH5.8moderately acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter1.5%low — add compost
Hydrologic groupCwater soaks in slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Urban land.

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 20810; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Bethesda, MD

Summer high88 °Faverage high, July
Winter low26 °Faverage low, January
Hot days44days a year at 90 °F or more
Freezing nights96nights a year at 32 °F or less
Growing degree days4,035base 50 °F — the season’s usable heat
Longest day14 h 54 mindaylight on June 21
Shortest day9 h 26 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation48.5 inper year, rain and melted snow
Snowfall6 inper year; 6 days with snow on the ground

Average high and low, by month

20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 43 °F, low 26 °F 43°26° JanFebruary: average high 46 °F, low 27 °F 46°27° FebMarch: average high 55 °F, low 34 °F 55°34° MarApril: average high 68 °F, low 44 °F 68°44° AprMay: average high 76 °F, low 54 °F 76°54° MayJune: average high 84 °F, low 63 °F 84°63° JunJuly: average high 88 °F, low 68 °F 88°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 56 °F, low 36 °F 56°36° NovDecember: average high 47 °F, low 30 °F 47°30° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″6″January: 3.32 in precipitation, 2.9 in snowfall 3.3❄3 JanFebruary: 3.24 in precipitation, 1.4 in snowfall 3.2❄1 FebMarch: 4.15 in precipitation, 0.7 in snowfall 4.2❄1 MarApril: 3.53 in precipitation 3.5 AprMay: 4.44 in precipitation 4.4 MayJune: 4.24 in precipitation 4.2 JunJuly: 5.11 in precipitation 5.1 JulAugust: 4.42 in precipitation 4.4 AugSeptember: 4.54 in precipitation 4.5 SepOctober: 4.40 in precipitation 4.4 OctNovember: 3.32 in precipitation 3.3 NovDecember: 3.81 in precipitation, 0.8 in snowfall 3.8❄1 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Dalecarlia Rsvr, MD (3 mi away); precipitation: Dalecarlia Rsvr, MD (3 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 7b.

208117b
Bethesda, MD · <1 mi
208247b
Bethesda, MD · <1 mi
208947b
Bethesda, MD · 1 mi
208157b
Chevy Chase, MD · 1 mi
208927b
Bethesda, MD · 1 mi
208147b
Bethesda, MD · 2 mi
208897b
Bethesda, MD · 2 mi
208167b
Bethesda, MD · 2 mi

All 11 ZIP codes in Bethesda → · Maryland planting zones →

Questions about 20810

What planting zone is ZIP code 20810?

ZIP code 20810 (Bethesda, 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 Bethesda, MD?

The median last spring frost (32 °F) near 20810 is April 9; after April 26 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Dalecarlia Rsvr station.

When is the first frost in Bethesda, MD?

The median first fall frost near 20810 is October 31, giving a median frost-free growing season of 202 days.

When should I plant tomatoes in 20810?

Start tomato seeds indoors around Feb 12 – Feb 26 and set transplants outside around Apr 16 – Apr 30, one to three weeks after the median last frost.

How much rain and snow does 20810 get?

About 48.5 inches of precipitation a year and 6 inches of snowfall (NOAA 1991–2020 normals, Dalecarlia Rsvr station).

How hot do summers get in Bethesda, MD?

The average high peaks at 88 °F in July, with about 44 days a year at 90 °F or more.

What kind of soil does 20810 have?

The USDA soil survey maps Udorthents at the center of ZIP 20810: loam, well drained, pH about 5.8 (moderately acidic).

Did spring come early in Bethesda, MD in 2026?

Spring leaf-out near 20810 came on Mar 10 in 2026, 6 days earlier than the 1991–2020 average (Mar 16), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Bethesda, MD?

Intermediate onions: the longest day near 20810 is 14 h 54 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 20810 change?

Yes. The 2012 USDA map put 20810 in zone 7a; the 2023 map puts it in zone 7b. The newer map uses 1991–2020 data and more weather stations.