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

Planting zone for 21161 — White Hall, MD

ZIP code 21161 (White Hall, Harford County) is in USDA zone 7a: the coldest winter night averages 0 to 5 °F. The median last spring frost is April 19 and the first fall frost October 25.

Where ZIP 21161 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.

Zone7a0 to 5 °F
Coldest night−17.8 to −15 °C
Last frostApr 19
First frostOct 25
2012 zone6b

Was 6b 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 7a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for White Hall, 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 White Hall, MD

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 19median — 50% chance of a later frost
Safe for tender plantsMay 8only 10% chance of frost after
First fall frostOctober 25median — 10% chance by Oct 8
Growing season188 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 5 and returns around November 4.

From the NOAA station Millers 4 Ne, MD — 13 miles away, elevation 860 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 21161

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 8 – Mar 22
SpinachSow outdoors · Mar 8 – Mar 29
Broccoli, cabbageStart indoors · Feb 8 – Feb 22
Broccoli, cabbageTransplant · Mar 29 – Apr 12
Onion setsPlant outdoors · Mar 22 – Apr 5
PotatoesPlant outdoors · Mar 29 – Apr 12
LettuceSow outdoors · Mar 22 – Apr 5
Carrots, beetsSow outdoors · Mar 29 – Apr 12
TomatoesStart indoors · Feb 22 – Mar 8
TomatoesTransplant · Apr 26 – May 10
Peppers, eggplantStart indoors · Feb 8 – Feb 22
Peppers, eggplantTransplant · May 3 – May 17
BeansSow outdoors · Apr 26 – May 10
Sweet cornSow outdoors · Apr 26 – May 10
Cucumbers, squashSow outdoors · Apr 26 – May 10
Fall lettuce, spinachSow outdoors · Aug 30 – Sep 13
GarlicPlant cloves · Oct 11 – Nov 15
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 19) and first fall frost (Oct 25) 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 21161 came on Mar 22 — about the same time as the 1991–2020 average (Mar 24).

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 White Hall, MD

The soil mapped at the center of ZIP 21161 is Chester — silt loam, well drained.

TextureSilt loama good balance for most vegetables
pH5.0strongly acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter3.25%moderate
Hydrologic groupBwater soaks in moderately
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Chester silt loam, 8 to 15 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 21161; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in White Hall, MD

Summer high85 °Faverage high, July
Winter low24 °Faverage low, January
Hot days12days a year at 90 °F or more
Freezing nights101nights a year at 32 °F or less
Growing degree days3,441base 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
Precipitation51.3 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 40 °F, low 24 °F 40°24° JanFebruary: average high 43 °F, low 25 °F 43°25° FebMarch: average high 52 °F, low 32 °F 52°32° MarApril: average high 65 °F, low 42 °F 65°42° AprMay: average high 73 °F, low 51 °F 73°51° MayJune: average high 81 °F, low 60 °F 81°60° JunJuly: average high 85 °F, low 64 °F 85°64° JulAugust: average high 83 °F, low 63 °F 83°63° AugSeptember: average high 77 °F, low 56 °F 77°56° SepOctober: average high 65 °F, low 45 °F 65°45° OctNovember: average high 54 °F, low 36 °F 54°36° NovDecember: average high 44 °F, low 28 °F 44°28° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 3.66 in precipitation 3.7 JanFebruary: 3.09 in precipitation 3.1 FebMarch: 4.60 in precipitation 4.6 MarApril: 3.97 in precipitation 4.0 AprMay: 4.55 in precipitation 4.5 MayJune: 5.03 in precipitation 5.0 JunJuly: 5.10 in precipitation 5.1 JulAugust: 4.15 in precipitation 4.2 AugSeptember: 4.96 in precipitation 5.0 SepOctober: 4.20 in precipitation 4.2 OctNovember: 3.59 in precipitation 3.6 NovDecember: 4.38 in precipitation 4.4 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Millers 4 Ne, MD (13 mi away); precipitation: Norrisville 0.6 Wsw, MD (3 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 7a.

211207a
Parkton, MD · 6 mi
211117a
Monkton, MD · 6 mi
211057a
Maryland Line, MD · 6 mi
210847a
Jarrettsville, MD · 6 mi
173637a
Stewartstown, PA · 7 mi
173497a
New Freedom, PA · 8 mi
173527a
New Park, PA · 8 mi
211327a
Pylesville, MD · 8 mi

Maryland planting zones →

Questions about 21161

What planting zone is ZIP code 21161?

ZIP code 21161 (White Hall, MD) is in USDA hardiness zone 7a on the 2023 map: the coldest night of an average winter reaches 0 to 5 °F (−17.8 to −15 °C).

When is the last frost in White Hall, MD?

The median last spring frost (32 °F) near 21161 is April 19; after May 8 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Millers 4 Ne station.

When is the first frost in White Hall, MD?

The median first fall frost near 21161 is October 25, giving a median frost-free growing season of 188 days.

When should I plant tomatoes in 21161?

Start tomato seeds indoors around Feb 22 – Mar 8 and set transplants outside around Apr 26 – May 10, one to three weeks after the median last frost.

How much rain and snow does 21161 get?

About 51.3 inches of precipitation a year (NOAA 1991–2020 normals, Norrisville 0.6 Wsw station).

How hot do summers get in White Hall, MD?

The average high peaks at 85 °F in July, with about 12 days a year at 90 °F or more.

What kind of soil does 21161 have?

The USDA soil survey maps Chester at the center of ZIP 21161: silt loam, well drained, pH about 5.0 (strongly acidic).

Did spring come early in White Hall, MD in 2026?

Spring leaf-out near 21161 came on Mar 22 in 2026, about the same as the 1991–2020 average (Mar 24), according to the USA National Phenology Network Spring Index.

What kind of onions grow in White Hall, MD?

Intermediate onions: the longest day near 21161 is 14 h 59 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 21161 change?

Yes. The 2012 USDA map put 21161 in zone 6b; the 2023 map puts it in zone 7a. The newer map uses 1991–2020 data and more weather stations.