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

Planting zone for 52601 — Burlington, IA

ZIP code 52601 (Burlington, Des Moines County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is April 15 and the first fall frost October 20.

Where ZIP 52601 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.

Zone6a−10 to −5 °F
Coldest night−23.3 to −20.6 °C
Last frostApr 15
First frostOct 20
2012 zone5b

Was 5b 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 6a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Burlington, 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 Burlington, IA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 15median — 50% chance of a later frost
Safe for tender plantsMay 1only 10% chance of frost after
First fall frostOctober 20median — 10% chance by Oct 6
Growing season187 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 5 and returns around October 31.

From the NOAA station Burlington Municipal Airport, IA — 5 miles away, elevation 692 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 52601

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 4 – Mar 18
SpinachSow outdoors · Mar 4 – Mar 25
Broccoli, cabbageStart indoors · Feb 4 – Feb 18
Broccoli, cabbageTransplant · Mar 25 – Apr 8
Onion setsPlant outdoors · Mar 18 – Apr 1
PotatoesPlant outdoors · Mar 25 – Apr 8
LettuceSow outdoors · Mar 18 – Apr 1
Carrots, beetsSow outdoors · Mar 25 – Apr 8
TomatoesStart indoors · Feb 18 – Mar 4
TomatoesTransplant · Apr 22 – May 6
Peppers, eggplantStart indoors · Feb 4 – Feb 18
Peppers, eggplantTransplant · Apr 29 – May 13
BeansSow outdoors · Apr 22 – May 6
Sweet cornSow outdoors · Apr 22 – May 6
Cucumbers, squashSow outdoors · Apr 22 – May 6
Fall lettuce, spinachSow outdoors · Aug 25 – Sep 8
GarlicPlant cloves · Oct 6 – Nov 10
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 15) and first fall frost (Oct 20) 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 52601 came on Mar 15 — 16 days earlier than the 1991–2020 average (Mar 31).

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 6a in Iowa

482 plants native to the lower 48 states, recorded in Iowa, and rated by the USDA to survive −10 °F or colder — the bottom of zone 6a. Each links to its USDA PLANTS profile.

Trees 49

American basswood100 ft · blooms late spring · low shade tolerance · to −46 °FAmerican chestnut115 ft · blooms early summer · high shade tolerance · to −33 °FAmerican elm120 ft · blooms early spring · medium shade tolerance · to −46 °FAmerican sycamore100 ft · blooms spring · medium shade tolerance · to −34 °Farborvitae50 ft · blooms mid spring · medium shade tolerance · to −33 °Fbalsam fir60 ft · blooms mid summer · low shade tolerance · to −43 °F

Shrubs 79

alderleaf buckthorn3 ft · blooms late spring · low shade tolerance · to −33 °FAllegheny serviceberry35 ft · blooms early spring · low shade tolerance · to −38 °Falternateleaf dogwood25 ft · blooms mid spring · low shade tolerance · to −47 °FAmerican black currant3 ft · blooms early spring · to −46 °FAmerican hazelnut10 ft · blooms spring · medium shade tolerance · to −33 °FAmerican hornbeam30 ft · blooms mid spring · low shade tolerance · to −34 °F

Wildflowers & perennials 195

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °FAmerican bur-reed3 ft · blooms indeterminate · medium shade tolerance · to −33 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °FAmerican licorice4 ft · blooms late spring · medium shade tolerance · to −38 °FAmerican lotus3 ft · blooms mid summer · high shade tolerance · to −36 °FAmerican pokeweed7 ft · blooms mid summer · low shade tolerance · to −33 °F

Grasses 137

arctic brome3 ft · blooms early summer · low shade tolerance · to −33 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °FBebb's sedge3 ft · blooms late spring · low shade tolerance · to −38 °FBicknell's sedge3 ft · blooms late spring · low shade tolerance · to −38 °Fbig bluestem6 ft · blooms summer · high shade tolerance · to −46 °Fblue grama1 ft · blooms early summer · high shade tolerance · to −43 °F

Vines 8

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °Fdevil's darning needles15 ft · blooms mid summer · medium shade tolerance · to −38 °Ffrost grape83 ft · blooms late spring · medium shade tolerance · to −23 °Friverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °Fsummer grape30 ft · blooms late spring · low shade tolerance · to −23 °Ftrumpet creeper2 ft · blooms summer · high shade tolerance · to −13 °F

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 Burlington, IA.

Soil in Burlington, IA

The soil mapped at the center of ZIP 52601 is Fayette — silt loam, well drained.

TextureSilt loama good balance for most vegetables
pH6.2slightly acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter3%moderate
Hydrologic groupCwater soaks in slowly
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Fayette silt loam, till plain, 5 to 9 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 52601; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Burlington, IA

Summer high85 °Faverage high, July
Winter low16 °Faverage low, January
Hot days23days a year at 90 °F or more
Freezing nights119nights a year at 32 °F or less
Growing degree days3,554base 50 °F — the season’s usable heat
Longest day15 h 07 mindaylight on June 21
Shortest day9 h 14 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation37.9 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 32 °F, low 16 °F 32°16° JanFebruary: average high 37 °F, low 21 °F 37°21° FebMarch: average high 50 °F, low 31 °F 50°31° MarApril: average high 63 °F, low 42 °F 63°42° AprMay: average high 73 °F, low 53 °F 73°53° MayJune: average high 82 °F, low 63 °F 82°63° JunJuly: average high 85 °F, low 66 °F 85°66° JulAugust: average high 84 °F, low 64 °F 84°64° AugSeptember: average high 78 °F, low 56 °F 78°56° SepOctober: average high 65 °F, low 44 °F 65°44° OctNovember: average high 50 °F, low 32 °F 50°32° NovDecember: average high 37 °F, low 22 °F 37°22° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 1.45 in precipitation 1.4 JanFebruary: 1.69 in precipitation 1.7 FebMarch: 2.43 in precipitation 2.4 MarApril: 3.92 in precipitation 3.9 AprMay: 4.93 in precipitation 4.9 MayJune: 4.87 in precipitation 4.9 JunJuly: 4.02 in precipitation 4.0 JulAugust: 3.77 in precipitation 3.8 AugSeptember: 3.53 in precipitation 3.5 SepOctober: 3.09 in precipitation 3.1 OctNovember: 2.29 in precipitation 2.3 NovDecember: 1.87 in precipitation 1.9 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Burlington Municipal Airport, IA (5 mi away); precipitation: Burlington Municipal Airport, IA (5 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.

526556a
West Burlington, IA · 4 mi
526506a
Sperry, IA · 7 mi
526386a
Middletown, IA · 7 mi
614376a
Gladstone, IL · 7 mi
614256a
Carman, IL · 8 mi
526236a
Danville, IA · 11 mi
526375b
Mediapolis, IA · 11 mi
526586a
Wever, IA · 12 mi

Iowa planting zones →

Questions about 52601

What planting zone is ZIP code 52601?

ZIP code 52601 (Burlington, IA) is in USDA hardiness zone 6a on the 2023 map: the coldest night of an average winter reaches −10 to −5 °F (−23.3 to −20.6 °C).

When is the last frost in Burlington, IA?

The median last spring frost (32 °F) near 52601 is April 15; after May 1 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Burlington Municipal Airport station.

When is the first frost in Burlington, IA?

The median first fall frost near 52601 is October 20, giving a median frost-free growing season of 187 days.

When should I plant tomatoes in 52601?

Start tomato seeds indoors around Feb 18 – Mar 4 and set transplants outside around Apr 22 – May 6, one to three weeks after the median last frost.

How much rain and snow does 52601 get?

About 37.9 inches of precipitation a year (NOAA 1991–2020 normals, Burlington Municipal Airport station).

How hot do summers get in Burlington, IA?

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 52601 have?

The USDA soil survey maps Fayette at the center of ZIP 52601: silt loam, well drained, pH about 6.2 (slightly acidic).

Did spring come early in Burlington, IA in 2026?

Spring leaf-out near 52601 came on Mar 15 in 2026, 16 days earlier than the 1991–2020 average (Mar 31), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Burlington, IA?

Long-day onions: the longest day near 52601 is 15 h 07 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 52601 change?

Yes. The 2012 USDA map put 52601 in zone 5b; the 2023 map puts it in zone 6a. The newer map uses 1991–2020 data and more weather stations.