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

Planting zone for 43512 — Defiance, OH

ZIP code 43512 (Defiance, Defiance County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is April 22 and the first fall frost October 24.

Where ZIP 43512 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.

Zone6a−10 to −5 °F
Coldest night−23.3 to −20.6 °C
Last frostApr 22
First frostOct 24
2012 zone6a

Same zone as on the 2012 map. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 6a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Defiance, 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 Defiance, OH

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 22median — 50% chance of a later frost
Safe for tender plantsMay 8only 10% chance of frost after
First fall frostOctober 24median — 10% chance by Oct 11
Growing season183 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 10 and returns around November 4.

From the NOAA station Defiance, OH — 2 miles away, elevation 699 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 43512

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 11 – Mar 25
SpinachSow outdoors · Mar 11 – Apr 1
Broccoli, cabbageStart indoors · Feb 11 – Feb 25
Broccoli, cabbageTransplant · Apr 1 – Apr 15
Onion setsPlant outdoors · Mar 25 – Apr 8
PotatoesPlant outdoors · Apr 1 – Apr 15
LettuceSow outdoors · Mar 25 – Apr 8
Carrots, beetsSow outdoors · Apr 1 – Apr 15
TomatoesStart indoors · Feb 25 – Mar 11
TomatoesTransplant · Apr 29 – May 13
Peppers, eggplantStart indoors · Feb 11 – Feb 25
Peppers, eggplantTransplant · May 6 – May 20
BeansSow outdoors · Apr 29 – May 13
Sweet cornSow outdoors · Apr 29 – May 13
Cucumbers, squashSow outdoors · Apr 29 – May 13
Fall lettuce, spinachSow outdoors · Aug 29 – Sep 12
GarlicPlant cloves · Oct 10 – Nov 14
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 22) and first fall frost (Oct 24) 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 43512 came on Mar 22 — 13 days earlier than the 1991–2020 average (Apr 4).

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).

Soil in Defiance, OH

The soil mapped at the center of ZIP 43512 is Nappanee — silty clay loam, somewhat poorly drained.

TextureSilty clay loamholds water and nutrients; slow to drain and warm up
pH6.2slightly acidic; most vegetables like 6.0–7.0
DrainageSomewhat poorly drainedconsider raised beds
Organic matter2%moderate
Hydrologic groupC/Dslow when drained; wet otherwise
Farmland classPrime farmland if drainedUSDA classification

Map unit: Nappanee silty clay loam, 0 to 3 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 43512; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Defiance, OH

Summer high85 °Faverage high, July
Winter low18 °Faverage low, January
Hot days17days a year at 90 °F or more
Freezing nights127nights a year at 32 °F or less
Growing degree days3,148base 50 °F — the season’s usable heat
Longest day15 h 10 mindaylight on June 21
Shortest day9 h 11 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation37.7 inper year, rain and melted snow
Snowfall24 inper year; 38 days with snow on the ground

Average high and low, by month

10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 32 °F, low 18 °F 32°18° JanFebruary: average high 36 °F, low 20 °F 36°20° FebMarch: average high 46 °F, low 28 °F 46°28° MarApril: average high 60 °F, low 38 °F 60°38° AprMay: average high 71 °F, low 50 °F 71°50° MayJune: average high 81 °F, low 60 °F 81°60° JunJuly: average high 85 °F, low 63 °F 85°63° JulAugust: average high 82 °F, low 62 °F 82°62° AugSeptember: average high 77 °F, low 54 °F 77°54° SepOctober: average high 63 °F, low 43 °F 63°43° OctNovember: average high 49 °F, low 32 °F 49°32° NovDecember: average high 37 °F, low 24 °F 37°24° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″January: 2.59 in precipitation, 8.7 in snowfall 2.6❄9 JanFebruary: 2.17 in precipitation, 8 in snowfall 2.2❄8 FebMarch: 2.55 in precipitation, 2.6 in snowfall 2.5❄3 MarApril: 3.67 in precipitation, 0.2 in snowfall 3.7 AprMay: 4.26 in precipitation 4.3 MayJune: 3.63 in precipitation 3.6 JunJuly: 3.66 in precipitation 3.7 JulAugust: 3.50 in precipitation 3.5 AugSeptember: 3.25 in precipitation 3.3 SepOctober: 2.87 in precipitation 2.9 OctNovember: 3.00 in precipitation, 0.9 in snowfall 3.0❄1 NovDecember: 2.55 in precipitation, 3.8 in snowfall 2.5❄4 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Defiance, OH (2 mi away); precipitation: Defiance, OH (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6a.

435306a
Jewell, OH · 4 mi
435196a
Evansport, OH · 8 mi
435496a
Ney, OH · 10 mi
435566a
Sherwood, OH · 11 mi
435556a
Ridgeville Corners, OH · 11 mi
435276a
Holgate, OH · 11 mi
458216a
Cecil, OH · 12 mi
435486a
New Bavaria, OH · 12 mi

Ohio planting zones →

Questions about 43512

What planting zone is ZIP code 43512?

ZIP code 43512 (Defiance, OH) is in USDA hardiness zone 6a on the 2023 map: the coldest night of an average winter reaches −10 to −5 °F (−23.3 to −20.6 °C).

When is the last frost in Defiance, OH?

The median last spring frost (32 °F) near 43512 is April 22; after May 8 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Defiance station.

When is the first frost in Defiance, OH?

The median first fall frost near 43512 is October 24, giving a median frost-free growing season of 183 days.

When should I plant tomatoes in 43512?

Start tomato seeds indoors around Feb 25 – Mar 11 and set transplants outside around Apr 29 – May 13, one to three weeks after the median last frost.

How much rain and snow does 43512 get?

About 37.7 inches of precipitation a year and 24 inches of snowfall (NOAA 1991–2020 normals, Defiance station).

How hot do summers get in Defiance, OH?

The average high peaks at 85 °F in July, with about 17 days a year at 90 °F or more.

What kind of soil does 43512 have?

The USDA soil survey maps Nappanee at the center of ZIP 43512: silty clay loam, somewhat poorly drained, pH about 6.2 (slightly acidic).

Did spring come early in Defiance, OH in 2026?

Spring leaf-out near 43512 came on Mar 22 in 2026, 13 days earlier than the 1991–2020 average (Apr 4), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Defiance, OH?

Long-day onions: the longest day near 43512 is 15 h 10 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).