Planting zone for 27310 — Oak Ridge, NC
ZIP code 27310 (Oak Ridge, Guilford County) is in USDA zone 8a: the coldest winter night averages 10 to 15 °F. The median last spring frost is March 30 and the first fall frost November 5.
Where ZIP 27310 is
Outlined: the ZIP code area · tap the map for the zone at any spot · scroll or pinch to zoomNot 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.
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 ServiceLoading the forecast for Oak Ridge, 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 Oak Ridge, NC
A hard freeze (28 °F) usually ends around March 18 and returns around November 17.
From the NOAA station Piedmont Triad Intl Airport, NC — 6 miles away, elevation 889 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 27310
Counted from the median last spring frost (Mar 30) and first fall frost (Nov 5) 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 27310 came on Feb 26 — about the same time as the 1991–2020 average (Feb 24).
Feb 242026
Feb 26
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.
Trees 92
Shrubs 136
Wildflowers & perennials 191
Grasses 173
Vines 12
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 Oak Ridge, NC.
Soil in Oak Ridge, NC
The soil mapped at the center of ZIP 27310 is Casville — sandy loam, well drained.
Map unit: Casville sandy loam, 2 to 6 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 27310; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.
Climate in Oak Ridge, NC
Average high and low, by month
Precipitation by month inches · ❄ = snowfall
NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Piedmont Triad Intl Airport, NC (6 mi away); precipitation: Piedmont Triad Intl Airport, NC (6 mi away). Daylight is calculated from latitude.
Nearby ZIP codes
All 8 nearest ZIP codes share zone 8a.
Questions about 27310
What planting zone is ZIP code 27310?
ZIP code 27310 (Oak Ridge, 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 Oak Ridge, NC?
The median last spring frost (32 °F) near 27310 is March 30; after April 14 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Piedmont Triad Intl Airport station.
When is the first frost in Oak Ridge, NC?
The median first fall frost near 27310 is November 5, giving a median frost-free growing season of 220 days.
When should I plant tomatoes in 27310?
Start tomato seeds indoors around Feb 2 – Feb 16 and set transplants outside around Apr 6 – Apr 20, one to three weeks after the median last frost.
How much rain and snow does 27310 get?
About 44 inches of precipitation a year and 7 inches of snowfall (NOAA 1991–2020 normals, Piedmont Triad Intl Airport station).
How hot do summers get in Oak Ridge, NC?
The average high peaks at 89 °F in July, with about 33 days a year at 90 °F or more.
What kind of soil does 27310 have?
The USDA soil survey maps Casville at the center of ZIP 27310: sandy loam, well drained, pH about 5.5 (moderately acidic).
Did spring come early in Oak Ridge, NC in 2026?
Spring leaf-out near 27310 came on Feb 26 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 Oak Ridge, NC?
Intermediate onions: the longest day near 27310 is 14 h 37 min, so day-neutral types bulb best; long-day varieties may not bulb fully.
Did the zone for 27310 change?
Yes. The 2012 USDA map put 27310 in zone 7b; the 2023 map puts it in zone 8a. The newer map uses 1991–2020 data and more weather stations.