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

Planting zone for 30665 — Siloam, GA

ZIP code 30665 (Siloam, Greene County) is in USDA zone 8b: the coldest winter night averages 15 to 20 °F. The median last spring frost is March 27 and the first fall frost November 8.

Where ZIP 30665 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 27

First frostNov 8

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 Siloam, 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 Siloam, GA

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMarch 27median — 50% chance of a later frost

Safe for tender plantsApril 13only 10% chance of frost after

First fall frostNovember 8median — 10% chance by Oct 25

Growing season226 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 12 and returns around November 23.

From the NOAA station Siloam 3n, GA — 2 miles away, elevation 696 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 30665

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Feb 13 – Feb 27

SpinachSow outdoors · Feb 13 – Mar 6

Broccoli, cabbageStart indoors · Jan 16 – Jan 30

Broccoli, cabbageTransplant · Mar 6 – Mar 20

Onion setsPlant outdoors · Feb 27 – Mar 13

PotatoesPlant outdoors · Mar 6 – Mar 20

LettuceSow outdoors · Feb 27 – Mar 13

Carrots, beetsSow outdoors · Mar 6 – Mar 20

TomatoesStart indoors · Jan 30 – Feb 13

TomatoesTransplant · Apr 3 – Apr 17

Peppers, eggplantStart indoors · Jan 16 – Jan 30

Peppers, eggplantTransplant · Apr 10 – Apr 24

BeansSow outdoors · Apr 3 – Apr 17

Sweet cornSow outdoors · Apr 3 – Apr 17

Cucumbers, squashSow outdoors · Apr 3 – Apr 17

Fall lettuce, spinachSow outdoors · Sep 13 – Sep 27

GarlicPlant cloves · Oct 25 – Nov 29

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 27) and first fall frost (Nov 8) 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 30665 came on Feb 15 — 7 days later than the 1991–2020 average (Feb 8).

average
Feb 82026
Feb 15

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 Siloam, GA.

Soil in Siloam, GA

The soil mapped at the center of ZIP 30665 is Cecil — gravelly sandy loam, well drained.

TextureGravelly sandy loamdrains and warms fast; dries out and needs more feeding

pH5.1strongly acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter0.75%low — add compost

Hydrologic groupBwater soaks in moderately

Farmland classprime farmlandUSDA classification

Map unit: Cecil gravelly sandy loam, 2 to 6 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 30665; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Siloam, GA

Summer high91 °Faverage high, July

Winter low32 °Faverage low, January

Hot days59days a year at 90 °F or more

Freezing nights59nights a year at 32 °F or less

Growing degree days5,113base 50 °F — the season’s usable heat

Longest day14 h 23 mindaylight on June 21

Shortest day9 h 55 mindaylight on December 21

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

Precipitation46.1 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: Siloam 3n, GA (2 mi away); precipitation: Siloam 3n, GA (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

306788b

White Plains, GA · 6 mi

306428b

Greensboro, GA · 6 mi

306698b

Union Point, GA · 10 mi

306318b

Crawfordville, GA · 12 mi

Georgia planting zones →

Questions about 30665

What planting zone is ZIP code 30665?

ZIP code 30665 (Siloam, 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 Siloam, GA?

The median last spring frost (32 °F) near 30665 is March 27; after April 13 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Siloam 3n station.

When is the first frost in Siloam, GA?

The median first fall frost near 30665 is November 8, giving a median frost-free growing season of 226 days.

When should I plant tomatoes in 30665?

Start tomato seeds indoors around Jan 30 – Feb 13 and set transplants outside around Apr 3 – Apr 17, one to three weeks after the median last frost.

How much rain and snow does 30665 get?

About 46.1 inches of precipitation a year (NOAA 1991–2020 normals, Siloam 3n station).

How hot do summers get in Siloam, GA?

The average high peaks at 91 °F in July, with about 59 days a year at 90 °F or more.

What kind of soil does 30665 have?

The USDA soil survey maps Cecil at the center of ZIP 30665: gravelly sandy loam, well drained, pH about 5.1 (strongly acidic).

Did spring come early in Siloam, GA in 2026?

Spring leaf-out near 30665 came on Feb 15 in 2026, 7 days later than the 1991–2020 average (Feb 8), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Siloam, GA?

Intermediate onions: the longest day near 30665 is 14 h 23 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 30665 change?

Yes. The 2012 USDA map put 30665 in zone 8a; the 2023 map puts it in zone 8b. The newer map uses 1991–2020 data and more weather stations.