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

Planting zone for Fairfield, OH

Fairfield, OH is in USDA zone 6b across its 2 ZIP codes. The median last spring frost is April 19 and the first fall frost October 22.

Fairfield on the zone map

Outlined: its 1 ZIP code areas · 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

ZIP codes2

Last frostApr 19

First frostOct 22

Growing season186 days

6b 2 ZIPs

Frost forecast — next 7 nights

live from the National Weather Service

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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 Fairfield, OH

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 19median — 50% chance of a later frost

Safe for tender plantsMay 7only 10% chance of frost after

First fall frostOctober 22median — 10% chance by Oct 9

Growing season186 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 6 and returns around November 1.

From the NOAA station Fairfield, OH, elevation 574 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 Fairfield

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 8 – Mar 22

SpinachSow outdoors · Mar 8 – Mar 29

Broccoli, cabbageStart indoors · Feb 8 – Feb 22

Broccoli, cabbageTransplant · Mar 29 – Apr 12

Onion setsPlant outdoors · Mar 22 – Apr 5

PotatoesPlant outdoors · Mar 29 – Apr 12

LettuceSow outdoors · Mar 22 – Apr 5

Carrots, beetsSow outdoors · Mar 29 – Apr 12

TomatoesStart indoors · Feb 22 – Mar 8

TomatoesTransplant · Apr 26 – May 10

Peppers, eggplantStart indoors · Feb 8 – Feb 22

Peppers, eggplantTransplant · May 3 – May 17

BeansSow outdoors · Apr 26 – May 10

Sweet cornSow outdoors · Apr 26 – May 10

Cucumbers, squashSow outdoors · Apr 26 – May 10

Fall lettuce, spinachSow outdoors · Aug 27 – Sep 10

GarlicPlant cloves · Oct 8 – Nov 12

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 19) and first fall frost (Oct 22) 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 45018 came on Mar 10 — 11 days earlier than the 1991–2020 average (Mar 21).

average
Mar 212026
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 Fairfield, OH.

Soil in Fairfield, OH

The soil mapped at the center of ZIP 45018 is Xenia — silt loam, moderately well drained.

TextureSilt loama good balance for most vegetables

pH6.6neutral; most vegetables like 6.0–7.0

DrainageModerately well drainednatural drainage class

Organic matter2%moderate

Hydrologic groupCwater soaks in slowly

Farmland classprime farmlandUSDA classification

Map unit: Xenia silt loam, bedrock substratum, 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 45018; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Fairfield, OH

Summer high87 °Faverage high, July

Winter low22 °Faverage low, January

Hot days28days a year at 90 °F or more

Freezing nights115nights a year at 32 °F or less

Growing degree days3,637base 50 °F — the season’s usable heat

Longest day14 h 57 mindaylight on June 21

Shortest day9 h 23 mindaylight on December 21

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

Precipitation41.4 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: Hamilton Butler Co. Regional Airport, OH (6 mi away); precipitation: Hamilton Butler Co. Regional Airport, OH (6 mi away). Daylight is calculated from latitude.

ZIP codes in Fairfield

Ohio planting zones →

Questions about Fairfield

What planting zone is Fairfield, OH?

Fairfield, OH is in USDA hardiness zone 6b on the 2023 map (6b: −5 to 0 °F).

When is the last frost in Fairfield, OH?

The median last spring frost is April 19 and the median first fall frost is October 22 (NOAA 1991–2020 normals, Fairfield station).

When can I plant a garden in Fairfield, OH?

Cool-season crops like peas and spinach go in around Mar 8 – Mar 29; tomatoes, peppers, beans and squash after about Apr 26, once frost risk has passed.

What kind of onions grow in Fairfield, OH?

Intermediate onions: the longest day is 14 h 57 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

How much rain and snow does Fairfield, OH get?

About 41.4 inches of precipitation a year (NOAA 1991–2020 normals).