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

Planting zone for 45245 — Cincinnati, OH

ZIP code 45245 (Cincinnati, Clermont County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is April 16 and the first fall frost October 25.

Where ZIP 45245 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 16
First frostOct 25
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 Cincinnati, 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 Cincinnati, OH

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 16median — 50% chance of a later frost
Safe for tender plantsMay 3only 10% chance of frost after
First fall frostOctober 25median — 10% chance by Oct 12
Growing season190 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 2 and returns around November 4.

From the NOAA station Cincinnati Lunken Airport, OH — 8 miles away, elevation 489 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 45245

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 5 – Mar 19
SpinachSow outdoors · Mar 5 – Mar 26
Broccoli, cabbageStart indoors · Feb 5 – Feb 19
Broccoli, cabbageTransplant · Mar 26 – Apr 9
Onion setsPlant outdoors · Mar 19 – Apr 2
PotatoesPlant outdoors · Mar 26 – Apr 9
LettuceSow outdoors · Mar 19 – Apr 2
Carrots, beetsSow outdoors · Mar 26 – Apr 9
TomatoesStart indoors · Feb 19 – Mar 5
TomatoesTransplant · Apr 23 – May 7
Peppers, eggplantStart indoors · Feb 5 – Feb 19
Peppers, eggplantTransplant · Apr 30 – May 14
BeansSow outdoors · Apr 23 – May 7
Sweet cornSow outdoors · Apr 23 – May 7
Cucumbers, squashSow outdoors · Apr 23 – May 7
Fall lettuce, spinachSow outdoors · Aug 30 – Sep 13
GarlicPlant cloves · Oct 11 – Nov 15
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 16) and first fall frost (Oct 25) 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 45245 came on Mar 8 — 10 days earlier than the 1991–2020 average (Mar 18).

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 Cincinnati, OH

The soil mapped at the center of ZIP 45245 is Rossmoyne — silt loam, moderately well drained.

TextureSilt loama good balance for most vegetables
pH5.9moderately acidic; most vegetables like 6.0–7.0
DrainageModerately well drainednatural drainage class
Organic matter2%moderate
Hydrologic groupDwater soaks in very slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Rossmoyne-Urban land complex, gently sloping.

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 45245; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Cincinnati, OH

Summer high87 °Faverage high, July
Winter low24 °Faverage low, January
Hot days27days a year at 90 °F or more
Freezing nights102nights a year at 32 °F or less
Growing degree days3,763base 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
Precipitation47.2 inper year, rain and melted snow

Average high and low, by month

10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 41 °F, low 24 °F 41°24° JanFebruary: average high 45 °F, low 26 °F 45°26° FebMarch: average high 55 °F, low 33 °F 55°33° MarApril: average high 67 °F, low 43 °F 67°43° AprMay: average high 75 °F, low 53 °F 75°53° MayJune: average high 83 °F, low 61 °F 83°61° JunJuly: average high 87 °F, low 65 °F 87°65° JulAugust: average high 86 °F, low 64 °F 86°64° AugSeptember: average high 80 °F, low 56 °F 80°56° SepOctober: average high 68 °F, low 44 °F 68°44° OctNovember: average high 55 °F, low 34 °F 55°34° NovDecember: average high 45 °F, low 28 °F 45°28° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 3.26 in precipitation 3.3 JanFebruary: 3.23 in precipitation 3.2 FebMarch: 4.07 in precipitation 4.1 MarApril: 5.00 in precipitation 5.0 AprMay: 5.01 in precipitation 5.0 MayJune: 4.87 in precipitation 4.9 JunJuly: 4.59 in precipitation 4.6 JulAugust: 3.33 in precipitation 3.3 AugSeptember: 3.52 in precipitation 3.5 SepOctober: 3.23 in precipitation 3.2 OctNovember: 3.29 in precipitation 3.3 NovDecember: 3.83 in precipitation 3.8 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Cincinnati Lunken Airport, OH (8 mi away); precipitation: Amelia 0.3 Ssw, OH (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6b.

452556b
Cincinnati, OH · 3 mi
452446b
Cincinnati, OH · 4 mi
451026b
Amelia, OH · 5 mi
410596b
Melbourne, KY · 6 mi
452306b
Cincinnati, OH · 6 mi
410856b
Silver Grove, KY · 6 mi
451746b
Terrace Park, OH · 7 mi
451036b
Batavia, OH · 8 mi

All 70 ZIP codes in Cincinnati → · Ohio planting zones →

Questions about 45245

What planting zone is ZIP code 45245?

ZIP code 45245 (Cincinnati, 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 Cincinnati, OH?

The median last spring frost (32 °F) near 45245 is April 16; after May 3 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Cincinnati Lunken Airport station.

When is the first frost in Cincinnati, OH?

The median first fall frost near 45245 is October 25, giving a median frost-free growing season of 190 days.

When should I plant tomatoes in 45245?

Start tomato seeds indoors around Feb 19 – Mar 5 and set transplants outside around Apr 23 – May 7, one to three weeks after the median last frost.

How much rain and snow does 45245 get?

About 47.2 inches of precipitation a year (NOAA 1991–2020 normals, Amelia 0.3 Ssw station).

How hot do summers get in Cincinnati, OH?

The average high peaks at 87 °F in July, with about 27 days a year at 90 °F or more.

What kind of soil does 45245 have?

The USDA soil survey maps Rossmoyne at the center of ZIP 45245: silt loam, moderately well drained, pH about 5.9 (moderately acidic).

Did spring come early in Cincinnati, OH in 2026?

Spring leaf-out near 45245 came on Mar 8 in 2026, 10 days earlier than the 1991–2020 average (Mar 18), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Cincinnati, OH?

Intermediate onions: the longest day near 45245 is 14 h 55 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 45245 change?

Yes. The 2012 USDA map put 45245 in zone 6a; the 2023 map puts it in zone 6b. The newer map uses 1991–2020 data and more weather stations.