Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for 28666 — Icard, NC

ZIP code 28666 (Icard, Burke County) is in USDA zone 8a: the coldest winter night averages 10 to 15 °F. The median last spring frost is March 31 and the first fall frost November 4.

Where ZIP 28666 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 31

First frostNov 4

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 Icard, 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 Icard, NC

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostMarch 31median — 50% chance of a later frost

Safe for tender plantsApril 16only 10% chance of frost after

First fall frostNovember 4median — 10% chance by Oct 22

Growing season219 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 18 and returns around November 15.

From the NOAA station Hickory Faa Airport, NC — 5 miles away, elevation 1,142 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 28666

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Feb 17 – Mar 3

SpinachSow outdoors · Feb 17 – Mar 10

Broccoli, cabbageStart indoors · Jan 20 – Feb 3

Broccoli, cabbageTransplant · Mar 10 – Mar 24

Onion setsPlant outdoors · Mar 3 – Mar 17

PotatoesPlant outdoors · Mar 10 – Mar 24

LettuceSow outdoors · Mar 3 – Mar 17

Carrots, beetsSow outdoors · Mar 10 – Mar 24

TomatoesStart indoors · Feb 3 – Feb 17

TomatoesTransplant · Apr 7 – Apr 21

Peppers, eggplantStart indoors · Jan 20 – Feb 3

Peppers, eggplantTransplant · Apr 14 – Apr 28

BeansSow outdoors · Apr 7 – Apr 21

Sweet cornSow outdoors · Apr 7 – Apr 21

Cucumbers, squashSow outdoors · Apr 7 – Apr 21

Fall lettuce, spinachSow outdoors · Sep 9 – Sep 23

GarlicPlant cloves · Oct 21 – Nov 25

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 31) and first fall frost (Nov 4) 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 28666 came on Feb 22 — about the same time as the 1991–2020 average (Feb 24).

average
Feb 242026
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 Icard, NC.

Soil in Icard, NC

The soil mapped at the center of ZIP 28666 is Fairview — sandy clay loam, well drained.

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

pH5.7moderately acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter1%low — add compost

Hydrologic groupBwater soaks in moderately

Farmland classprime farmlandUSDA classification

Map unit: Fairview sandy clay loam, 2 to 8 percent slopes, moderately eroded.

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 28666; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Icard, NC

Summer high87 °Faverage high, July

Winter low30 °Faverage low, January

Hot days33days a year at 90 °F or more

Freezing nights69nights a year at 32 °F or less

Growing degree days4,412base 50 °F — the season’s usable heat

Longest day14 h 35 mindaylight on June 21

Shortest day9 h 44 mindaylight on December 21

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

Precipitation47.3 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: Hickory Faa Airport, NC (5 mi away); precipitation: Rhodhiss Hydro Plt, NC (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

286378a

Hildebran, NC · 3 mi

286718a

Rutherford College, NC · 4 mi

Connelly Springs, NC · 6 mi

286197b

Drexel, NC · 8 mi

286308a

Granite Falls, NC · 8 mi

North Carolina planting zones →

Questions about 28666

What planting zone is ZIP code 28666?

ZIP code 28666 (Icard, 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 Icard, NC?

The median last spring frost (32 °F) near 28666 is March 31; after April 16 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Hickory Faa Airport station.

When is the first frost in Icard, NC?

The median first fall frost near 28666 is November 4, giving a median frost-free growing season of 219 days.

When should I plant tomatoes in 28666?

Start tomato seeds indoors around Feb 3 – Feb 17 and set transplants outside around Apr 7 – Apr 21, one to three weeks after the median last frost.

How much rain and snow does 28666 get?

About 47.3 inches of precipitation a year (NOAA 1991–2020 normals, Rhodhiss Hydro Plt station).

How hot do summers get in Icard, NC?

The average high peaks at 87 °F in July, with about 33 days a year at 90 °F or more.

What kind of soil does 28666 have?

The USDA soil survey maps Fairview at the center of ZIP 28666: sandy clay loam, well drained, pH about 5.7 (moderately acidic).

Did spring come early in Icard, NC in 2026?

Spring leaf-out near 28666 came on Feb 22 in 2026, about the same as the 1991–2020 average (Feb 24), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Icard, NC?

Intermediate onions: the longest day near 28666 is 14 h 35 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 28666 change?

Yes. The 2012 USDA map put 28666 in zone 7b; the 2023 map puts it in zone 8a. The newer map uses 1991–2020 data and more weather stations.