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

Planting zone for 21632 — Federalsburg, MD

ZIP code 21632 (Federalsburg, Caroline County) is in USDA zone 7b: the coldest winter night averages 5 to 10 °F. The median last spring frost is April 11 and the first fall frost October 30.

Where ZIP 21632 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 11
First frostOct 30
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 Federalsburg, 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 Federalsburg, MD

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 11median — 50% chance of a later frost
Safe for tender plantsApril 28only 10% chance of frost after
First fall frostOctober 30median — 10% chance by Oct 14
Growing season200 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 30 and returns around November 11.

From the NOAA station Greenwood 2ne, DE — 12 miles away, elevation 46 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 21632

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Feb 28 – Mar 14
SpinachSow outdoors · Feb 28 – Mar 21
Broccoli, cabbageStart indoors · Jan 31 – Feb 14
Broccoli, cabbageTransplant · Mar 21 – Apr 4
Onion setsPlant outdoors · Mar 14 – Mar 28
PotatoesPlant outdoors · Mar 21 – Apr 4
LettuceSow outdoors · Mar 14 – Mar 28
Carrots, beetsSow outdoors · Mar 21 – Apr 4
TomatoesStart indoors · Feb 14 – Feb 28
TomatoesTransplant · Apr 18 – May 2
Peppers, eggplantStart indoors · Jan 31 – Feb 14
Peppers, eggplantTransplant · Apr 25 – May 9
BeansSow outdoors · Apr 18 – May 2
Sweet cornSow outdoors · Apr 18 – May 2
Cucumbers, squashSow outdoors · Apr 18 – May 2
Fall lettuce, spinachSow outdoors · Sep 4 – Sep 18
GarlicPlant cloves · Oct 16 – Nov 20
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 11) and first fall frost (Oct 30) 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 21632 came on Mar 11 — about the same time as the 1991–2020 average (Mar 11).

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).

Soil in Federalsburg, MD

The soil mapped at the center of ZIP 21632 is Fallsington — mucky peat, poorly drained.

TextureMucky peattop layer
pH5.2strongly acidic; most vegetables like 6.0–7.0
DrainagePoorly drainedconsider raised beds
Organic matter68%high
Hydrologic groupB/Dmoderate when drained; wet otherwise
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Fallsington sandy loams, 0 to 2 percent slopes, Northern Tidewater Area.

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 21632; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Federalsburg, MD

Summer high87 °Faverage high, July
Winter low25 °Faverage low, January
Hot days22days a year at 90 °F or more
Freezing nights96nights a year at 32 °F or less
Growing degree days3,757base 50 °F — the season’s usable heat
Longest day14 h 53 mindaylight on June 21
Shortest day9 h 27 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation48.3 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 44 °F, low 25 °F 44°25° JanFebruary: average high 46 °F, low 26 °F 46°26° FebMarch: average high 54 °F, low 33 °F 54°33° MarApril: average high 65 °F, low 42 °F 65°42° AprMay: average high 73 °F, low 52 °F 73°52° MayJune: average high 82 °F, low 62 °F 82°62° JunJuly: average high 87 °F, low 67 °F 87°67° JulAugust: average high 85 °F, low 65 °F 85°65° AugSeptember: average high 79 °F, low 58 °F 79°58° SepOctober: average high 68 °F, low 46 °F 68°46° OctNovember: average high 57 °F, low 37 °F 57°37° NovDecember: average high 48 °F, low 29 °F 48°29° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 3.24 in precipitation 3.2 JanFebruary: 3.05 in precipitation 3.0 FebMarch: 4.23 in precipitation 4.2 MarApril: 3.50 in precipitation 3.5 AprMay: 3.98 in precipitation 4.0 MayJune: 4.37 in precipitation 4.4 JunJuly: 5.27 in precipitation 5.3 JulAugust: 4.92 in precipitation 4.9 AugSeptember: 5.15 in precipitation 5.2 SepOctober: 3.90 in precipitation 3.9 OctNovember: 2.92 in precipitation 2.9 NovDecember: 3.77 in precipitation 3.8 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Greenwood 2ne, DE (12 mi away); precipitation: Seaford 0.6 S, DE (11 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 7b.

216557b
Preston, MD · 8 mi
216437b
Hurlock, MD · 8 mi
199337b
Bridgeville, DE · 9 mi
216297b
Denton, MD · 9 mi
216097b
Bethlehem, MD · 10 mi
199737b
Seaford, DE · 10 mi
216597b
Rhodesdale, MD · 11 mi
199507b
Greenwood, DE · 11 mi

Maryland planting zones →

Questions about 21632

What planting zone is ZIP code 21632?

ZIP code 21632 (Federalsburg, 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 Federalsburg, MD?

The median last spring frost (32 °F) near 21632 is April 11; after April 28 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Greenwood 2ne station.

When is the first frost in Federalsburg, MD?

The median first fall frost near 21632 is October 30, giving a median frost-free growing season of 200 days.

When should I plant tomatoes in 21632?

Start tomato seeds indoors around Feb 14 – Feb 28 and set transplants outside around Apr 18 – May 2, one to three weeks after the median last frost.

How much rain and snow does 21632 get?

About 48.3 inches of precipitation a year (NOAA 1991–2020 normals, Seaford 0.6 S station).

How hot do summers get in Federalsburg, MD?

The average high peaks at 87 °F in July, with about 22 days a year at 90 °F or more.

What kind of soil does 21632 have?

The USDA soil survey maps Fallsington at the center of ZIP 21632: mucky peat, poorly drained, pH about 5.2 (strongly acidic).

Did spring come early in Federalsburg, MD in 2026?

Spring leaf-out near 21632 came on Mar 11 in 2026, about the same as the 1991–2020 average (Mar 11), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Federalsburg, MD?

Intermediate onions: the longest day near 21632 is 14 h 53 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 21632 change?

Yes. The 2012 USDA map put 21632 in zone 7a; the 2023 map puts it in zone 7b. The newer map uses 1991–2020 data and more weather stations.