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

Planting zone for 45787 — Watertown, OH

ZIP code 45787 (Watertown, Washington County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is April 24 and the first fall frost October 22.

Where ZIP 45787 is

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 24
First frostOct 22
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 Watertown, 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 Watertown, OH

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 24median — 50% chance of a later frost
Safe for tender plantsMay 11only 10% chance of frost after
First fall frostOctober 22median — 10% chance by Oct 9
Growing season178 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 13 and returns around November 1.

From the NOAA station Beverly Stp, OH — 6 miles away, elevation 623 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 45787

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 13 – Mar 27
SpinachSow outdoors · Mar 13 – Apr 3
Broccoli, cabbageStart indoors · Feb 13 – Feb 27
Broccoli, cabbageTransplant · Apr 3 – Apr 17
Onion setsPlant outdoors · Mar 27 – Apr 10
PotatoesPlant outdoors · Apr 3 – Apr 17
LettuceSow outdoors · Mar 27 – Apr 10
Carrots, beetsSow outdoors · Apr 3 – Apr 17
TomatoesStart indoors · Feb 27 – Mar 13
TomatoesTransplant · May 1 – May 15
Peppers, eggplantStart indoors · Feb 13 – Feb 27
Peppers, eggplantTransplant · May 8 – May 22
BeansSow outdoors · May 1 – May 15
Sweet cornSow outdoors · May 1 – May 15
Cucumbers, squashSow outdoors · May 1 – May 15
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 24) 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 45787 came on Mar 9 — 13 days earlier than the 1991–2020 average (Mar 22).

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 Watertown, OH

The soil mapped at the center of ZIP 45787 is Vincent — 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 groupDwater soaks in very slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Vincent silt loam, 6 to 12 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 45787; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Watertown, OH

Summer high85 °Faverage high, July
Winter low21 °Faverage low, January
Hot days23days a year at 90 °F or more
Freezing nights123nights a year at 32 °F or less
Growing degree days3,411base 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
Precipitation44.5 inper year, rain and melted snow
Snowfall16 inper year

Average high and low, by month

10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 38 °F, low 21 °F 38°21° JanFebruary: average high 42 °F, low 23 °F 42°23° FebMarch: average high 52 °F, low 30 °F 52°30° MarApril: average high 65 °F, low 40 °F 65°40° AprMay: average high 74 °F, low 50 °F 74°50° MayJune: average high 82 °F, low 60 °F 82°60° JunJuly: average high 85 °F, low 64 °F 85°64° JulAugust: average high 84 °F, low 62 °F 84°62° AugSeptember: average high 78 °F, low 54 °F 78°54° SepOctober: average high 67 °F, low 42 °F 67°42° OctNovember: average high 54 °F, low 32 °F 54°32° NovDecember: average high 43 °F, low 26 °F 43°26° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″January: 3.60 in precipitation, 7.1 in snowfall 3.6❄7 JanFebruary: 3.08 in precipitation, 4.3 in snowfall 3.1❄4 FebMarch: 4.08 in precipitation, 1.8 in snowfall 4.1❄2 MarApril: 3.61 in precipitation, 0.1 in snowfall 3.6 AprMay: 4.44 in precipitation 4.4 MayJune: 4.58 in precipitation 4.6 JunJuly: 4.60 in precipitation 4.6 JulAugust: 3.60 in precipitation 3.6 AugSeptember: 3.64 in precipitation 3.6 SepOctober: 2.96 in precipitation 3.0 OctNovember: 3.03 in precipitation, 0.2 in snowfall 3.0 NovDecember: 3.31 in precipitation, 2.2 in snowfall 3.3❄2 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Beverly Stp, OH (6 mi away); precipitation: Beverly Stp, OH (6 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6b.

457866b
Waterford, OH · 3 mi
457296b
Fleming, OH · 4 mi
457126b
Barlow, OH · 5 mi
457846b
Vincent, OH · 6 mi
457216b
Coal Run, OH · 7 mi
457446b
Lowell, OH · 9 mi
437876b
Stockport, OH · 10 mi
457156b
Beverly, OH · 10 mi

Ohio planting zones →

Questions about 45787

What planting zone is ZIP code 45787?

ZIP code 45787 (Watertown, 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 Watertown, OH?

The median last spring frost (32 °F) near 45787 is April 24; after May 11 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Beverly Stp station.

When is the first frost in Watertown, OH?

The median first fall frost near 45787 is October 22, giving a median frost-free growing season of 178 days.

When should I plant tomatoes in 45787?

Start tomato seeds indoors around Feb 27 – Mar 13 and set transplants outside around May 1 – May 15, one to three weeks after the median last frost.

How much rain and snow does 45787 get?

About 44.5 inches of precipitation a year and 16 inches of snowfall (NOAA 1991–2020 normals, Beverly Stp station).

How hot do summers get in Watertown, OH?

The average high peaks at 85 °F in July, with about 23 days a year at 90 °F or more.

What kind of soil does 45787 have?

The USDA soil survey maps Vincent at the center of ZIP 45787: silt loam, well drained, pH about 5.9 (moderately acidic).

Did spring come early in Watertown, OH in 2026?

Spring leaf-out near 45787 came on Mar 9 in 2026, 13 days earlier than the 1991–2020 average (Mar 22), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Watertown, OH?

Intermediate onions: the longest day near 45787 is 14 h 57 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 45787 change?

Yes. The 2012 USDA map put 45787 in zone 6a; the 2023 map puts it in zone 6b. The newer map uses 1991–2020 data and more weather stations.