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

Planting zone for 45688 — Waterloo, OH

ZIP code 45688 (Waterloo, Lawrence County) is in USDA zone 7a: the coldest winter night averages 0 to 5 °F. The median last spring frost is April 30 and the first fall frost October 15.

Where ZIP 45688 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.

Zone7a0 to 5 °F
Coldest night−17.8 to −15 °C
Last frostApr 30
First frostOct 15
2012 zone6a

Was 6a on the 2012 map — a full zone warmer now. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 7a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Waterloo, 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 Waterloo, OH

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 30median — 50% chance of a later frost
Safe for tender plantsMay 16only 10% chance of frost after
First fall frostOctober 15median — 10% chance by Oct 3
Growing season167 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 18 and returns around October 25.

From the NOAA station Waterloo, OH — 4 miles away, elevation 627 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 45688

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 19 – Apr 2
SpinachSow outdoors · Mar 19 – Apr 9
Broccoli, cabbageStart indoors · Feb 19 – Mar 5
Broccoli, cabbageTransplant · Apr 9 – Apr 23
Onion setsPlant outdoors · Apr 2 – Apr 16
PotatoesPlant outdoors · Apr 9 – Apr 23
LettuceSow outdoors · Apr 2 – Apr 16
Carrots, beetsSow outdoors · Apr 9 – Apr 23
TomatoesStart indoors · Mar 5 – Mar 19
TomatoesTransplant · May 7 – May 21
Peppers, eggplantStart indoors · Feb 19 – Mar 5
Peppers, eggplantTransplant · May 14 – May 28
BeansSow outdoors · May 7 – May 21
Sweet cornSow outdoors · May 7 – May 21
Cucumbers, squashSow outdoors · May 7 – May 21
Fall lettuce, spinachSow outdoors · Aug 20 – Sep 3
GarlicPlant cloves · Oct 1 – Nov 5
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 30) and first fall frost (Oct 15) 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 45688 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 Waterloo, OH

The soil mapped at the center of ZIP 45688 is Steinsburg — loam, well drained.

TextureLoama good balance for most vegetables
pH4.6strongly acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter2%moderate
Hydrologic groupBwater soaks in moderately
Farmland classNot prime farmlandUSDA classification

Map unit: Steinsburg-Shelocta association, very steep.

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 45688; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Waterloo, OH

Summer high86 °Faverage high, July
Winter low20 °Faverage low, January
Hot days27days a year at 90 °F or more
Freezing nights131nights a year at 32 °F or less
Growing degree days3,315base 50 °F — the season’s usable heat
Longest day14 h 53 mindaylight on June 21
Shortest day9 h 27 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation45.7 inper year, rain and melted snow
Snowfall14 inper year

Average high and low, by month

10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 41 °F, low 20 °F 41°20° JanFebruary: average high 45 °F, low 22 °F 45°22° FebMarch: average high 54 °F, low 29 °F 54°29° MarApril: average high 67 °F, low 38 °F 67°38° AprMay: average high 75 °F, low 49 °F 75°49° MayJune: average high 83 °F, low 58 °F 83°58° JunJuly: average high 86 °F, low 62 °F 86°62° JulAugust: average high 85 °F, low 60 °F 85°60° AugSeptember: average high 79 °F, low 52 °F 79°52° SepOctober: average high 68 °F, low 40 °F 68°40° OctNovember: average high 55 °F, low 30 °F 55°30° NovDecember: average high 46 °F, low 25 °F 46°25° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″6″January: 3.28 in precipitation, 5 in snowfall 3.3❄5 JanFebruary: 3.15 in precipitation, 3.9 in snowfall 3.1❄4 FebMarch: 4.19 in precipitation, 2.2 in snowfall 4.2❄2 MarApril: 3.69 in precipitation, 0.1 in snowfall 3.7 AprMay: 4.45 in precipitation 4.5 MayJune: 4.05 in precipitation 4.0 JunJuly: 5.57 in precipitation 5.6 JulAugust: 3.67 in precipitation 3.7 AugSeptember: 3.88 in precipitation 3.9 SepOctober: 3.10 in precipitation 3.1 OctNovember: 2.94 in precipitation, 0.4 in snowfall 2.9 NovDecember: 3.72 in precipitation, 2 in snowfall 3.7❄2 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Waterloo, OH (4 mi away); precipitation: Waterloo, OH (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

2 of the 8 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

456586b
Patriot, OH · 7 mi
456597a
Pedro, OH · 7 mi
456827a
South Webster, OH · 10 mi
456967a
Willow Wood, OH · 10 mi
456566b
Oak Hill, OH · 10 mi
456457a
Kitts Hill, OH · 11 mi
456787a
Scottown, OH · 12 mi
456777a
Scioto Furnace, OH · 12 mi

Ohio planting zones →

Questions about 45688

What planting zone is ZIP code 45688?

ZIP code 45688 (Waterloo, OH) is in USDA hardiness zone 7a on the 2023 map: the coldest night of an average winter reaches 0 to 5 °F (−17.8 to −15 °C).

When is the last frost in Waterloo, OH?

The median last spring frost (32 °F) near 45688 is April 30; after May 16 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Waterloo station.

When is the first frost in Waterloo, OH?

The median first fall frost near 45688 is October 15, giving a median frost-free growing season of 167 days.

When should I plant tomatoes in 45688?

Start tomato seeds indoors around Mar 5 – Mar 19 and set transplants outside around May 7 – May 21, one to three weeks after the median last frost.

How much rain and snow does 45688 get?

About 45.7 inches of precipitation a year and 14 inches of snowfall (NOAA 1991–2020 normals, Waterloo station).

How hot do summers get in Waterloo, OH?

The average high peaks at 86 °F in July, with about 27 days a year at 90 °F or more.

What kind of soil does 45688 have?

The USDA soil survey maps Steinsburg at the center of ZIP 45688: loam, well drained, pH about 4.6 (strongly acidic).

Did spring come early in Waterloo, OH in 2026?

Spring leaf-out near 45688 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 Waterloo, OH?

Intermediate onions: the longest day near 45688 is 14 h 53 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 45688 change?

Yes. The 2012 USDA map put 45688 in zone 6a; the 2023 map puts it in zone 7a. The newer map uses 1991–2020 data and more weather stations.