Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 30, 2026

Planting zone for 28123 — Mount Mourne, NC

ZIP code 28123 (Mount Mourne, Iredell County) is in USDA zone 8a: the coldest winter night averages 10 to 15 °F. The median last spring frost is April 9 and the first fall frost October 28.

Where ZIP 28123 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.

Zone8a10 to 15 °F

Coldest night−12.2 to −9.4 °C

Last frostApr 9

First frostOct 28

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 Mount Mourne, NC…

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 Mount Mourne, NC

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 24only 10% chance of frost after

First fall frostOctober 28median — 10% chance by Oct 15

Growing season203 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 28 and returns around November 6.

From the NOAA station Salisbury 9 Wnw, NC — 17 miles away, elevation 725 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 28123

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 2 – Sep 16

GarlicPlant cloves · Oct 14 – Nov 18

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 9) and first fall frost (Oct 28) 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 28123 came on Feb 22 — about the same time as the 1991–2020 average (Feb 21).

average
Feb 212026
Feb 22

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 North Carolina

619 plants native to the lower 48 states, recorded in North Carolina, and rated by the USDA to survive 10 °F or colder — the bottom of zone 8a. Each links to its USDA PLANTS profile.

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 Mount Mourne, NC.

Soil in Mount Mourne, NC

The soil mapped at the center of ZIP 28123 is Udorthents — sandy clay loam, well drained.

TextureSandy clay loamholds water and nutrients; slow to drain and warm up

pH6.2slightly acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter0.5%low — add compost

Hydrologic groupCwater soaks in slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Udorthents-Urban land complex, 0 to 45 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 28123; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Mount Mourne, NC

Summer high89 °Faverage high, July

Winter low27 °Faverage low, January

Hot days36days a year at 90 °F or more

Freezing nights93nights a year at 32 °F or less

Growing degree days4,393base 50 °F — the season’s usable heat

Longest day14 h 34 mindaylight on June 21

Shortest day9 h 45 mindaylight on December 21

Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully

Precipitation46.5 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Salisbury 9 Wnw, NC (17 mi away); precipitation: China Grove 4.4 W, NC (11 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 8a.

280358a

Davidson, NC · 3 mi

281178a

Mooresville, NC · 3 mi

281158a

Mooresville, NC · 5 mi

Huntersville, NC · 9 mi

281668a

Troutman, NC · 9 mi

North Carolina planting zones →

Questions about 28123

What planting zone is ZIP code 28123?

ZIP code 28123 (Mount Mourne, NC) 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 Mount Mourne, NC?

The median last spring frost (32 °F) near 28123 is April 9; after April 24 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Salisbury 9 Wnw station.

When is the first frost in Mount Mourne, NC?

The median first fall frost near 28123 is October 28, giving a median frost-free growing season of 203 days.

When should I plant tomatoes in 28123?

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 28123 get?

About 46.5 inches of precipitation a year (NOAA 1991–2020 normals, China Grove 4.4 W station).

How hot do summers get in Mount Mourne, NC?

The average high peaks at 89 °F in July, with about 36 days a year at 90 °F or more.

What kind of soil does 28123 have?

The USDA soil survey maps Udorthents at the center of ZIP 28123: sandy clay loam, well drained, pH about 6.2 (slightly acidic).

Did spring come early in Mount Mourne, NC in 2026?

Spring leaf-out near 28123 came on Feb 22 in 2026, about the same as the 1991–2020 average (Feb 21), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Mount Mourne, NC?

Intermediate onions: the longest day near 28123 is 14 h 34 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 28123 change?

Yes. The 2012 USDA map put 28123 in zone 7b; the 2023 map puts it in zone 8a. The newer map uses 1991–2020 data and more weather stations.