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

Planting zone for 52336 — Springville, IA

ZIP code 52336 (Springville, Linn County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is April 27 and the first fall frost October 13.

Where ZIP 52336 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.

Zone5a−20 to −15 °F
Coldest night−28.9 to −26.1 °C
Last frostApr 27
First frostOct 13
2012 zone5a

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 5a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Springville, IA…

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 Springville, IA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 27median — 50% chance of a later frost
Safe for tender plantsMay 10only 10% chance of frost after
First fall frostOctober 13median — 10% chance by Sep 30
Growing season170 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 14 and returns around October 24.

From the NOAA station Anamosa 3 Ssw, IA — 7 miles away, elevation 906 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 52336

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 16 – Mar 30
SpinachSow outdoors · Mar 16 – Apr 6
Broccoli, cabbageStart indoors · Feb 16 – Mar 2
Broccoli, cabbageTransplant · Apr 6 – Apr 20
Onion setsPlant outdoors · Mar 30 – Apr 13
PotatoesPlant outdoors · Apr 6 – Apr 20
LettuceSow outdoors · Mar 30 – Apr 13
Carrots, beetsSow outdoors · Apr 6 – Apr 20
TomatoesStart indoors · Mar 2 – Mar 16
TomatoesTransplant · May 4 – May 18
Peppers, eggplantStart indoors · Feb 16 – Mar 2
Peppers, eggplantTransplant · May 11 – May 25
BeansSow outdoors · May 4 – May 18
Sweet cornSow outdoors · May 4 – May 18
Cucumbers, squashSow outdoors · May 4 – May 18
Fall lettuce, spinachSow outdoors · Aug 18 – Sep 1
GarlicPlant cloves · Sep 29 – Nov 3
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 27) and first fall frost (Oct 13) 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 52336 came on Mar 25 — 14 days earlier than the 1991–2020 average (Apr 8).

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 5a in Iowa

461 plants native to the lower 48 states, recorded in Iowa, and rated by the USDA to survive −20 °F or colder — the bottom of zone 5a. Each links to its USDA PLANTS profile.

Trees 46

Shrubs 77

Wildflowers & perennials 185

Grasses 133

Vines 7

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 Springville, IA.

Soil in Springville, IA

The soil mapped at the center of ZIP 52336 is Spillville — loam, somewhat poorly drained.

TextureLoama good balance for most vegetables
pH6.7neutral; most vegetables like 6.0–7.0
DrainageSomewhat poorly drainedconsider raised beds
Organic matter5.5%high
Hydrologic groupB/Dmoderate when drained; wet otherwise
Farmland classprime farmlandUSDA classification

Map unit: Spillville loam, 0 to 2 percent slopes, occasionally flooded.

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 52336; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Springville, IA

Summer high83 °Faverage high, July
Winter low11 °Faverage low, January
Hot days9days a year at 90 °F or more
Freezing nights149nights a year at 32 °F or less
Growing degree days2,817base 50 °F — the season’s usable heat
Longest day15 h 15 mindaylight on June 21
Shortest day9 h 06 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation39.3 inper year, rain and melted snow

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 29 °F, low 11 °F 29°11° JanFebruary: average high 33 °F, low 15 °F 33°15° FebMarch: average high 45 °F, low 26 °F 45°26° MarApril: average high 59 °F, low 37 °F 59°37° AprMay: average high 70 °F, low 48 °F 70°48° MayJune: average high 80 °F, low 58 °F 80°58° JunJuly: average high 83 °F, low 62 °F 83°62° JulAugust: average high 81 °F, low 59 °F 81°59° AugSeptember: average high 75 °F, low 51 °F 75°51° SepOctober: average high 62 °F, low 40 °F 62°40° OctNovember: average high 47 °F, low 28 °F 47°28° NovDecember: average high 34 °F, low 18 °F 34°18° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 1.26 in precipitation 1.3 JanFebruary: 1.47 in precipitation 1.5 FebMarch: 2.22 in precipitation 2.2 MarApril: 4.00 in precipitation 4.0 AprMay: 4.69 in precipitation 4.7 MayJune: 5.53 in precipitation 5.5 JunJuly: 4.53 in precipitation 4.5 JulAugust: 4.82 in precipitation 4.8 AugSeptember: 3.70 in precipitation 3.7 SepOctober: 3.12 in precipitation 3.1 OctNovember: 2.19 in precipitation 2.2 NovDecember: 1.77 in precipitation 1.8 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Anamosa 3 Ssw, IA (7 mi away); precipitation: Anamosa 3 Ssw, IA (7 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.

Iowa planting zones →

Questions about 52336

What planting zone is ZIP code 52336?

ZIP code 52336 (Springville, IA) is in USDA hardiness zone 5a on the 2023 map: the coldest night of an average winter reaches −20 to −15 °F (−28.9 to −26.1 °C).

When is the last frost in Springville, IA?

The median last spring frost (32 °F) near 52336 is April 27; after May 10 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Anamosa 3 Ssw station.

When is the first frost in Springville, IA?

The median first fall frost near 52336 is October 13, giving a median frost-free growing season of 170 days.

When should I plant tomatoes in 52336?

Start tomato seeds indoors around Mar 2 – Mar 16 and set transplants outside around May 4 – May 18, one to three weeks after the median last frost.

How much rain and snow does 52336 get?

About 39.3 inches of precipitation a year (NOAA 1991–2020 normals, Anamosa 3 Ssw station).

How hot do summers get in Springville, IA?

The average high peaks at 83 °F in July, with about 9 days a year at 90 °F or more.

What kind of soil does 52336 have?

The USDA soil survey maps Spillville at the center of ZIP 52336: loam, somewhat poorly drained, pH about 6.7 (neutral).

Did spring come early in Springville, IA in 2026?

Spring leaf-out near 52336 came on Mar 25 in 2026, 14 days earlier than the 1991–2020 average (Apr 8), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Springville, IA?

Long-day onions: the longest day near 52336 is 15 h 15 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).