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

Planting zone for 50655 — Maynard, IA

ZIP code 50655 (Maynard, Fayette 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 50655 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 zone4b

Was 4b 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 5a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Maynard, 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 Maynard, 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 season169 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 15 and returns around October 22.

From the NOAA station Oelwein 1e, IA — 6 miles away, elevation 1,165 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 50655

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 50655 came on Mar 28 — 16 days earlier than the 1991–2020 average (Apr 13).

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 Maynard, IA.

Soil in Maynard, IA

The soil mapped at the center of ZIP 50655 is Kenyon — loam, moderately well drained.

TextureLoama good balance for most vegetables
pH5.8moderately acidic; most vegetables like 6.0–7.0
DrainageModerately well drainednatural drainage class
Organic matter2.9%moderate
Hydrologic groupCwater soaks in slowly
Farmland classprime farmlandUSDA classification

Map unit: Kenyon loam, 2 to 5 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 50655; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Maynard, IA

Summer high83 °Faverage high, July
Winter low9 °Faverage low, January
Hot days9days a year at 90 °F or more
Freezing nights156nights a year at 32 °F or less
Growing degree days2,989base 50 °F — the season’s usable heat
Longest day15 h 20 mindaylight on June 21
Shortest day9 h 02 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation35.4 inper year, rain and melted snow
Snowfall39 inper year; 72 days with snow on the ground

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 27 °F, low 9 °F 27°9° JanFebruary: average high 31 °F, low 12 °F 31°12° FebMarch: average high 45 °F, low 24 °F 45°24° MarApril: average high 59 °F, low 37 °F 59°37° AprMay: average high 71 °F, low 49 °F 71°49° MayJune: average high 81 °F, low 60 °F 81°60° JunJuly: average high 83 °F, low 63 °F 83°63° JulAugust: average high 81 °F, low 61 °F 81°61° AugSeptember: average high 76 °F, low 52 °F 76°52° SepOctober: average high 63 °F, low 40 °F 63°40° OctNovember: average high 46 °F, low 27 °F 46°27° NovDecember: average high 33 °F, low 16 °F 33°16° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″6″January: 1.14 in precipitation, 8.7 in snowfall 1.1❄9 JanFebruary: 1.06 in precipitation, 10.9 in snowfall 1.1❄11 FebMarch: 1.93 in precipitation, 4.4 in snowfall 1.9❄4 MarApril: 3.52 in precipitation, 2.2 in snowfall 3.5❄2 AprMay: 4.24 in precipitation, 0.1 in snowfall 4.2 MayJune: 5.43 in precipitation 5.4 JunJuly: 5.31 in precipitation 5.3 JulAugust: 3.85 in precipitation 3.9 AugSeptember: 3.38 in precipitation 3.4 SepOctober: 2.56 in precipitation, 0.3 in snowfall 2.6 OctNovember: 1.56 in precipitation, 1.8 in snowfall 1.6❄2 NovDecember: 1.38 in precipitation, 10.9 in snowfall 1.4❄11 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Oelwein 1e, IA (6 mi away); precipitation: Oelwein 1e, IA (6 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

1 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 50655

What planting zone is ZIP code 50655?

ZIP code 50655 (Maynard, 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 Maynard, IA?

The median last spring frost (32 °F) near 50655 is April 27; after May 10 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Oelwein 1e station.

When is the first frost in Maynard, IA?

The median first fall frost near 50655 is October 13, giving a median frost-free growing season of 169 days.

When should I plant tomatoes in 50655?

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 50655 get?

About 35.4 inches of precipitation a year and 39 inches of snowfall (NOAA 1991–2020 normals, Oelwein 1e station).

How hot do summers get in Maynard, 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 50655 have?

The USDA soil survey maps Kenyon at the center of ZIP 50655: loam, moderately well drained, pH about 5.8 (moderately acidic).

Did spring come early in Maynard, IA in 2026?

Spring leaf-out near 50655 came on Mar 28 in 2026, 16 days earlier than the 1991–2020 average (Apr 13), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Maynard, IA?

Long-day onions: the longest day near 50655 is 15 h 20 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 50655 change?

Yes. The 2012 USDA map put 50655 in zone 4b; the 2023 map puts it in zone 5a. The newer map uses 1991–2020 data and more weather stations.