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

Planting zone for 31780 — Plains, GA

ZIP code 31780 (Plains, Sumter County) is in USDA zone 8b: the coldest winter night averages 15 to 20 °F. The median last spring frost is March 15 and the first fall frost November 17.

Where ZIP 31780 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.

Zone8b15 to 20 °F

Coldest night−9.4 to −6.7 °C

Last frostMar 15

First frostNov 17

2012 zone8a

Was 8a 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 8b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Plains, GA…

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 Plains, GA

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMarch 15median — 50% chance of a later frost

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

First fall frostNovember 17median — 10% chance by Nov 1

Growing season249 daysfrost-free, median

A hard freeze (28 °F) usually ends around February 28 and returns around December 1.

From the NOAA station Plains Sw Ga Exp Stn, GA — 2 miles away, elevation 499 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 31780

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Feb 1 – Feb 15

SpinachSow outdoors · Feb 1 – Feb 22

Broccoli, cabbageStart indoors · Jan 4 – Jan 18

Broccoli, cabbageTransplant · Feb 22 – Mar 8

Onion setsPlant outdoors · Feb 15 – Mar 1

PotatoesPlant outdoors · Feb 22 – Mar 8

LettuceSow outdoors · Feb 15 – Mar 1

Carrots, beetsSow outdoors · Feb 22 – Mar 8

TomatoesStart indoors · Jan 18 – Feb 1

TomatoesTransplant · Mar 22 – Apr 5

Peppers, eggplantStart indoors · Jan 4 – Jan 18

Peppers, eggplantTransplant · Mar 29 – Apr 12

BeansSow outdoors · Mar 22 – Apr 5

Sweet cornSow outdoors · Mar 22 – Apr 5

Cucumbers, squashSow outdoors · Mar 22 – Apr 5

Fall lettuce, spinachSow outdoors · Sep 22 – Oct 6

GarlicPlant cloves · Nov 3 – Dec 8

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 15) and first fall frost (Nov 17) 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 31780 came on Feb 6 — 4 days later than the 1991–2020 average (Feb 2).

average
Feb 22026
Feb 6

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 8b in Georgia

590 plants native to the lower 48 states, recorded in Georgia, and rated by the USDA to survive 15 °F or colder — the bottom of zone 8b. 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 Plains, GA.

Soil in Plains, GA

The soil mapped at the center of ZIP 31780 is Faceville — sandy loam, well drained.

TextureSandy loamdrains and warms fast; dries out and needs more feeding

pH5.3strongly acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter1.25%low — add compost

Hydrologic groupBwater soaks in moderately

Farmland classprime farmlandUSDA classification

Map unit: Faceville sandy loam, 2 to 5 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 31780; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Plains, GA

Summer high90 °Faverage high, July

Winter low36 °Faverage low, January

Hot days72days a year at 90 °F or more

Freezing nights42nights a year at 32 °F or less

Growing degree days5,771base 50 °F — the season’s usable heat

Longest day14 h 15 mindaylight on June 21

Shortest day10 h 03 mindaylight on December 21

Onions to growShort-daysummer days stay under about 14 h 20 min, so long-day varieties won’t bulb

Precipitation50.7 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: Plains Sw Ga Exp Stn, GA (2 mi away); precipitation: Plains Sw Ga Exp Stn, GA (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 8b.

Smithville, GA · 12 mi

Ellaville, GA · 17 mi

Georgia planting zones →

Questions about 31780

What planting zone is ZIP code 31780?

ZIP code 31780 (Plains, GA) is in USDA hardiness zone 8b on the 2023 map: the coldest night of an average winter reaches 15 to 20 °F (−9.4 to −6.7 °C).

When is the last frost in Plains, GA?

The median last spring frost (32 °F) near 31780 is March 15; after April 2 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Plains Sw Ga Exp Stn station.

When is the first frost in Plains, GA?

The median first fall frost near 31780 is November 17, giving a median frost-free growing season of 249 days.

When should I plant tomatoes in 31780?

Start tomato seeds indoors around Jan 18 – Feb 1 and set transplants outside around Mar 22 – Apr 5, one to three weeks after the median last frost.

How much rain and snow does 31780 get?

About 50.7 inches of precipitation a year (NOAA 1991–2020 normals, Plains Sw Ga Exp Stn station).

How hot do summers get in Plains, GA?

The average high peaks at 90 °F in July, with about 72 days a year at 90 °F or more.

What kind of soil does 31780 have?

The USDA soil survey maps Faceville at the center of ZIP 31780: sandy loam, well drained, pH about 5.3 (strongly acidic).

Did spring come early in Plains, GA in 2026?

Spring leaf-out near 31780 came on Feb 6 in 2026, 4 days later than the 1991–2020 average (Feb 2), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Plains, GA?

Short-day onions: the longest day near 31780 is 14 h 15 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.

Did the zone for 31780 change?

Yes. The 2012 USDA map put 31780 in zone 8a; the 2023 map puts it in zone 8b. The newer map uses 1991–2020 data and more weather stations.