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

Planting zone for 45171 — Sardinia, OH

ZIP code 45171 (Sardinia, Brown County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is April 29 and the first fall frost October 11.

Where ZIP 45171 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.

Zone6b−5 to 0 °F

Coldest night−20.6 to −17.8 °C

Last frostApr 29

First frostOct 11

2012 zone6a

Was 6a 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 6b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Sardinia, OH…

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 Sardinia, OH

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 29median — 50% chance of a later frost

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

First fall frostOctober 11median — 10% chance by Sep 28

Growing season162 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 20 and returns around October 21.

From the NOAA station Ripley Exp Farm, OH — 16 miles away, elevation 879 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 45171

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 18 – Apr 1

SpinachSow outdoors · Mar 18 – Apr 8

Broccoli, cabbageStart indoors · Feb 18 – Mar 4

Broccoli, cabbageTransplant · Apr 8 – Apr 22

Onion setsPlant outdoors · Apr 1 – Apr 15

PotatoesPlant outdoors · Apr 8 – Apr 22

LettuceSow outdoors · Apr 1 – Apr 15

Carrots, beetsSow outdoors · Apr 8 – Apr 22

TomatoesStart indoors · Mar 4 – Mar 18

TomatoesTransplant · May 6 – May 20

Peppers, eggplantStart indoors · Feb 18 – Mar 4

Peppers, eggplantTransplant · May 13 – May 27

BeansSow outdoors · May 6 – May 20

Sweet cornSow outdoors · May 6 – May 20

Cucumbers, squashSow outdoors · May 6 – May 20

Fall lettuce, spinachSow outdoors · Aug 16 – Aug 30

GarlicPlant cloves · Sep 27 – Nov 1

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 29) and first fall frost (Oct 11) 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 45171 came on Mar 10 — 12 days earlier than the 1991–2020 average (Mar 22).

average
Mar 222026
Mar 10

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 6b in Ohio

570 plants native to the lower 48 states, recorded in Ohio, and rated by the USDA to survive −5 °F or colder — the bottom of zone 6b. 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 Sardinia, OH.

Soil in Sardinia, OH

The soil mapped at the center of ZIP 45171 is Bonnell — silt loam, well drained.

TextureSilt loama good balance for most vegetables

pH5.9moderately acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter2%moderate

Hydrologic groupCwater soaks in slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Bonnell silt loam, 15 to 25 percent slopes, 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 45171; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Sardinia, OH

Summer high86 °Faverage high, July

Winter low17 °Faverage low, January

Hot days21days a year at 90 °F or more

Freezing nights128nights a year at 32 °F or less

Growing degree days3,172base 50 °F — the season’s usable heat

Longest day14 h 55 mindaylight on June 21

Shortest day9 h 25 mindaylight on December 21

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

Precipitation48.2 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: Ripley Exp Farm, OH (16 mi away); precipitation: Fayetteville 0.5 W, OH (14 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6b.

451556b

Mowrystown, OH · 3 mi

451546b

Mount Orab, OH · 7 mi

456976b

Winchester, OH · 9 mi

451686b

Russellville, OH · 11 mi

451216b

Georgetown, OH · 12 mi

456796b

Seaman, OH · 12 mi

451186b

Fayetteville, OH · 13 mi

451306b

Hamersville, OH · 13 mi

Ohio planting zones →

Questions about 45171

What planting zone is ZIP code 45171?

ZIP code 45171 (Sardinia, OH) is in USDA hardiness zone 6b on the 2023 map: the coldest night of an average winter reaches −5 to 0 °F (−20.6 to −17.8 °C).

When is the last frost in Sardinia, OH?

The median last spring frost (32 °F) near 45171 is April 29; after May 16 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Ripley Exp Farm station.

When is the first frost in Sardinia, OH?

The median first fall frost near 45171 is October 11, giving a median frost-free growing season of 162 days.

When should I plant tomatoes in 45171?

Start tomato seeds indoors around Mar 4 – Mar 18 and set transplants outside around May 6 – May 20, one to three weeks after the median last frost.

How much rain and snow does 45171 get?

About 48.2 inches of precipitation a year (NOAA 1991–2020 normals, Fayetteville 0.5 W station).

How hot do summers get in Sardinia, OH?

The average high peaks at 86 °F in July, with about 21 days a year at 90 °F or more.

What kind of soil does 45171 have?

The USDA soil survey maps Bonnell at the center of ZIP 45171: silt loam, well drained, pH about 5.9 (moderately acidic).

Did spring come early in Sardinia, OH in 2026?

Spring leaf-out near 45171 came on Mar 10 in 2026, 12 days earlier than the 1991–2020 average (Mar 22), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Sardinia, OH?

Intermediate onions: the longest day near 45171 is 14 h 55 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 45171 change?

Yes. The 2012 USDA map put 45171 in zone 6a; the 2023 map puts it in zone 6b. The newer map uses 1991–2020 data and more weather stations.