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

Planting zone for 28733 — Fontana Dam, NC

ZIP code 28733 (Fontana Dam, Graham County) is in USDA zone 7b: the coldest winter night averages 5 to 10 °F. The median last spring frost is April 13 and the first fall frost October 26.

Where ZIP 28733 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 13

First frostOct 26

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 Fontana Dam, 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 Fontana Dam, NC

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 13median — 50% chance of a later frost

Safe for tender plantsMay 2only 10% chance of frost after

First fall frostOctober 26median — 10% chance by Oct 12

Growing season194 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 31 and returns around November 3.

From the NOAA station Robbinsville Ag 5 Ne, NC — 6 miles away, elevation 2,330 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 28733

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 2 – Mar 16

SpinachSow outdoors · Mar 2 – Mar 23

Broccoli, cabbageStart indoors · Feb 2 – Feb 16

Broccoli, cabbageTransplant · Mar 23 – Apr 6

Onion setsPlant outdoors · Mar 16 – Mar 30

PotatoesPlant outdoors · Mar 23 – Apr 6

LettuceSow outdoors · Mar 16 – Mar 30

Carrots, beetsSow outdoors · Mar 23 – Apr 6

TomatoesStart indoors · Feb 16 – Mar 2

TomatoesTransplant · Apr 20 – May 4

Peppers, eggplantStart indoors · Feb 2 – Feb 16

Peppers, eggplantTransplant · Apr 27 – May 11

BeansSow outdoors · Apr 20 – May 4

Sweet cornSow outdoors · Apr 20 – May 4

Cucumbers, squashSow outdoors · Apr 20 – May 4

Fall lettuce, spinachSow outdoors · Aug 31 – Sep 14

GarlicPlant cloves · Oct 12 – Nov 16

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 13) and first fall frost (Oct 26) 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 28733 came on Mar 1 — 6 days earlier than the 1991–2020 average (Mar 7).

average
Mar 72026
Mar 1

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 7b in North Carolina

596 plants native to the lower 48 states, recorded in North Carolina, and rated by the USDA to survive 5 °F or colder — the bottom of zone 7b. 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 Fontana Dam, NC.

Soil in Fontana Dam, NC

The soil mapped at the center of ZIP 28733 is Spivey — very flaggy loam, well drained.

TextureVery flaggy loama good balance for most vegetables

pH4.8strongly acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter10%high

Hydrologic groupAwater soaks in fast

Farmland classNot prime farmlandUSDA classification

Map unit: Spivey-Whiteoak complex, 15 to 30 percent slopes, bouldery.

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 28733; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Fontana Dam, NC

Summer high83 °Faverage high, July

Winter low26 °Faverage low, January

Hot days8days a year at 90 °F or more

Freezing nights96nights a year at 32 °F or less

Growing degree days3,463base 50 °F — the season’s usable heat

Longest day14 h 33 mindaylight on June 21

Shortest day9 h 46 mindaylight on December 21

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

Precipitation63.6 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: Robbinsville Ag 5 Ne, NC (6 mi away); precipitation: Robbinsville Ag 5 Ne, NC (6 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

287717a

Robbinsville, NC · 7 mi

Bryson City, NC · 16 mi

Tallassee, TN · 16 mi

North Carolina planting zones →

Questions about 28733

What planting zone is ZIP code 28733?

ZIP code 28733 (Fontana Dam, NC) 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 Fontana Dam, NC?

The median last spring frost (32 °F) near 28733 is April 13; after May 2 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Robbinsville Ag 5 Ne station.

When is the first frost in Fontana Dam, NC?

The median first fall frost near 28733 is October 26, giving a median frost-free growing season of 194 days.

When should I plant tomatoes in 28733?

Start tomato seeds indoors around Feb 16 – Mar 2 and set transplants outside around Apr 20 – May 4, one to three weeks after the median last frost.

How much rain and snow does 28733 get?

About 63.6 inches of precipitation a year (NOAA 1991–2020 normals, Robbinsville Ag 5 Ne station).

How hot do summers get in Fontana Dam, NC?

The average high peaks at 83 °F in July, with about 8 days a year at 90 °F or more.

What kind of soil does 28733 have?

The USDA soil survey maps Spivey at the center of ZIP 28733: very flaggy loam, well drained, pH about 4.8 (strongly acidic).

Did spring come early in Fontana Dam, NC in 2026?

Spring leaf-out near 28733 came on Mar 1 in 2026, 6 days earlier than the 1991–2020 average (Mar 7), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Fontana Dam, NC?

Intermediate onions: the longest day near 28733 is 14 h 33 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 28733 change?

Yes. The 2012 USDA map put 28733 in zone 7a; the 2023 map puts it in zone 7b. The newer map uses 1991–2020 data and more weather stations.