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

Planting zone for 21409 — Annapolis, MD

ZIP code 21409 (Annapolis, Anne Arundel County) is in USDA zone 8a: the coldest winter night averages 10 to 15 °F. The median last spring frost is March 23 and the first fall frost November 20.

Where ZIP 21409 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.

Zone8a10 to 15 °F
Coldest night−12.2 to −9.4 °C
Last frostMar 23
First frostNov 20
2012 zone7b

Was 7b 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 8a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Annapolis, 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 Annapolis, MD

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMarch 23median — 50% chance of a later frost
Safe for tender plantsApril 6only 10% chance of frost after
First fall frostNovember 20median — 10% chance by Nov 4
Growing season241 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 12 and returns around December 3.

From the NOAA station Annapolis Naf, MD — 2 miles away, elevation 7 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 21409

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Feb 9 – Feb 23
SpinachSow outdoors · Feb 9 – Mar 2
Broccoli, cabbageStart indoors · Jan 12 – Jan 26
Broccoli, cabbageTransplant · Mar 2 – Mar 16
Onion setsPlant outdoors · Feb 23 – Mar 9
PotatoesPlant outdoors · Mar 2 – Mar 16
LettuceSow outdoors · Feb 23 – Mar 9
Carrots, beetsSow outdoors · Mar 2 – Mar 16
TomatoesStart indoors · Jan 26 – Feb 9
TomatoesTransplant · Mar 30 – Apr 13
Peppers, eggplantStart indoors · Jan 12 – Jan 26
Peppers, eggplantTransplant · Apr 6 – Apr 20
BeansSow outdoors · Mar 30 – Apr 13
Sweet cornSow outdoors · Mar 30 – Apr 13
Cucumbers, squashSow outdoors · Mar 30 – Apr 13
Fall lettuce, spinachSow outdoors · Sep 25 – Oct 9
GarlicPlant cloves · Nov 6 – Dec 11
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 23) and first fall frost (Nov 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 21409 came on Mar 13 — about the same time as the 1991–2020 average (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 8a in Maryland

629 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 8a. Each links to its USDA PLANTS profile.

Trees 84

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 129

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 209

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 181

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 Annapolis, MD.

Soil in Annapolis, MD

The soil mapped at the center of ZIP 21409 is Cumberstone — silt loam, somewhat poorly drained.

TextureSilt loama good balance for most vegetables
pH4.5strongly acidic; most vegetables like 6.0–7.0
DrainageSomewhat poorly drainedconsider raised beds
Organic matter5.2%high
Hydrologic groupC/Dslow when drained; wet otherwise
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Cumberstone-Mattapex complex, 0 to 2 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 21409; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Annapolis, MD

Summer high86 °Faverage high, July
Winter low30 °Faverage low, January
Hot days20days a year at 90 °F or more
Freezing nights56nights a year at 32 °F or less
Growing degree days4,246base 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
Precipitation44 inper year, rain and melted snow

Average high and low, by month

20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 43 °F, low 30 °F 43°30° JanFebruary: average high 45 °F, low 32 °F 45°32° FebMarch: average high 53 °F, low 38 °F 53°38° MarApril: average high 64 °F, low 47 °F 64°47° AprMay: average high 73 °F, low 57 °F 73°57° MayJune: average high 82 °F, low 68 °F 82°68° JunJuly: average high 86 °F, low 72 °F 86°72° JulAugust: average high 84 °F, low 71 °F 84°71° AugSeptember: average high 77 °F, low 65 °F 77°65° SepOctober: average high 67 °F, low 52 °F 67°52° OctNovember: average high 56 °F, low 42 °F 56°42° NovDecember: average high 47 °F, low 34 °F 47°34° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 2.84 in precipitation 2.8 JanFebruary: 2.38 in precipitation 2.4 FebMarch: 3.80 in precipitation 3.8 MarApril: 3.38 in precipitation 3.4 AprMay: 3.15 in precipitation 3.1 MayJune: 4.04 in precipitation 4.0 JunJuly: 4.94 in precipitation 4.9 JulAugust: 4.27 in precipitation 4.3 AugSeptember: 5.14 in precipitation 5.1 SepOctober: 4.04 in precipitation 4.0 OctNovember: 3.03 in precipitation 3.0 NovDecember: 2.98 in precipitation 3.0 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Annapolis Naf, MD (2 mi away); precipitation: Annapolis Naf, MD (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

214028a
Annapolis, MD · 3 mi
210128a
Arnold, MD · 3 mi
214048a
Annapolis, MD · 4 mi
210568a
Gibson Island, MD · 4 mi
214058a
Annapolis, MD · 6 mi
214038a
Annapolis, MD · 6 mi
214017b
Annapolis, MD · 6 mi
211228a
Pasadena, MD · 7 mi

All 8 ZIP codes in Annapolis → · Maryland planting zones →

Questions about 21409

What planting zone is ZIP code 21409?

ZIP code 21409 (Annapolis, MD) is in USDA hardiness zone 8a on the 2023 map: the coldest night of an average winter reaches 10 to 15 °F (−12.2 to −9.4 °C).

When is the last frost in Annapolis, MD?

The median last spring frost (32 °F) near 21409 is March 23; after April 6 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Annapolis Naf station.

When is the first frost in Annapolis, MD?

The median first fall frost near 21409 is November 20, giving a median frost-free growing season of 241 days.

When should I plant tomatoes in 21409?

Start tomato seeds indoors around Jan 26 – Feb 9 and set transplants outside around Mar 30 – Apr 13, one to three weeks after the median last frost.

How much rain and snow does 21409 get?

About 44 inches of precipitation a year (NOAA 1991–2020 normals, Annapolis Naf station).

How hot do summers get in Annapolis, MD?

The average high peaks at 86 °F in July, with about 20 days a year at 90 °F or more.

What kind of soil does 21409 have?

The USDA soil survey maps Cumberstone at the center of ZIP 21409: silt loam, somewhat poorly drained, pH about 4.5 (strongly acidic).

Did spring come early in Annapolis, MD in 2026?

Spring leaf-out near 21409 came on Mar 13 in 2026, about the same as the 1991–2020 average (Mar 12), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Annapolis, MD?

Intermediate onions: the longest day near 21409 is 14 h 55 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 21409 change?

Yes. The 2012 USDA map put 21409 in zone 7b; the 2023 map puts it in zone 8a. The newer map uses 1991–2020 data and more weather stations.