Hamburg, Iowa, sits in USDA hardiness zone 5b — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
Reliable performers under these conditions include cabbage, cranberry, lavender, and collard greens; what your own ground favors still comes down to its soil, sun, and drainage.
Even in Hamburg, no two yards are alike.
A low spot, a south-facing slope, or a stand of trees moves the frost date and sun across a single Hamburg lot. Enter your address and we'll score 1,086 plants against your land's actual soil, sun, and frost.
We read public map data around Hamburg — soil, climate, flood, and parcel records. How we handle your address.
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Hamburg — the short answer
Hamburg, Iowa: USDA zone 5b, about 203 days between hard freezes, across 958 acres of city.
- USDA zone
- 5b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 6
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 26
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~203
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 958 acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are this town’s own 28°F normals: light frosts run a few weeks past them, and tender transplants usually wait 2–3 weeks after the last hard freeze.
Hardiness Zone Range
Zone 5b is Hamburg's average, not your lot's — a low corner or a tree line moves it. Against Hamburg's 203-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Hamburg
Each reading below is measured for Hamburg itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredHamburg runs about 203 days between hard freezes — a long growing season.
There is slack for succession plantings and slow-finishing crops: many vegetables can be sown twice, and the heat-lovers have time to ripen fully.
Plan a second sowing of quick crops after the first comes out, and use the fall window most gardeners let sit idle.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredHamburg sits in USDA hardiness zone 5b.
The zone sets which perennials, shrubs, and fruit trees live through an average winter here — a plant rated for a colder zone is a safe bet, one rated warmer needs winter protection or gets treated as an annual.
Match perennials and fruit to the zone before you buy, so nothing you plant is a gamble against the cold.
USDA PHZM 2023
The kind of country Hamburg is in
Hamburg sits in the Western Corn Belt Plains — EPA Level III, inside the wider Great Plains. That is read at Hamburg's own centroid rather than borrowed from Fremont County.
What Grows in Hamburg
Every plant below cleared Hamburg's own zone 5b and its 203-day season. Each card opens that plant's Iowa profile. How we score.
Is it too late to plant in Hamburg?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Mar 9; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 6 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 26 — long-season crops need about 90 days of runway, quick greens only 30. Here the season winds down slowly: late sowings, a real autumn harvest, and garlic in the ground before the first hard freeze.
What's on the federal record near Hamburg
Closest first, within ~10 miles of Hamburg. Listing isn't leaking, and distance isn't exposure.
- GLEN STENZELUnderground Storage Tanks · 450 ft
- HAMBURG COMMUNITY SCHOOLSUnderground Storage Tanks · 750 ft
- HAMBURG JUNIOR-SENIOR HIGH SCHOOLBrownfields · 750 ft
- KEIM FARM EQUIPBrownfields · 750 ft
- BAILEY OIL COMPANYUnderground Storage Tanks · 800 ft
- CASEY''S GENERAL STORE 1330Underground Storage Tanks · 850 ft
- HAMBURG OIL COMPANYUnderground Storage Tanks · 850 ft
- CHARLIES STANDARDUnderground Storage Tanks · 900 ft
- FORMERLY GOOD SEED & GRAIN COUnderground Storage Tanks · 1100 ft
- CITY OF HAMBURGUnderground Storage Tanks · 1600 ft
- HOLT GASUnderground Storage Tanks · 2100 ft
- VOGELToxics Release Inventory · 2600 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Hamburg's center, not your beds. Run your own address for what's upwind of you specifically.
Environmental Intelligence
The counts behind that headline — every source type on the record near Hamburg.
Total Sites
74
within ~10 miles of Hamburg
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
within ~10 miles of Hamburg
Severity Distribution
within ~10 miles of Hamburg
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Hamburg, two things run higher than the national average within ~10 miles of Hamburg — Toxics Release Inventory (7 sites) and Nitrate (20 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Toxics Release Inventory: TRI facilities report annual chemical releases to air, water, and land.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Hamburg
Get exact proximity distances to contamination sources for your specific parcel — plus soil, sun, drainage, and 1,086 plant recommendations.
25+ data sources read at your address, not the Hamburg average
Your land is one point inside Hamburg
Everything above resolves to Hamburg as a whole — one PHZM band and one 28°F frost record, read across 958 acres. Your parcel is one point inside that footprint. Slope, tree cover, a low spot that pools cold air, and what is in the soil are all resolved at the address, and none of them are visible at city scale. That is the honest boundary of this page, and the reason the next step is a reading of your own ground rather than a better local average.
Your Lot vs the Hamburg Average
Hamburg Average
- ●USDA Zones 5b, averaged across Hamburg
- ●One soil character for all of Hamburg
- ●Frost dates read at Hamburg's scale: Apr 6 to Oct 26
YOUR Parcel
- ✓Your exact zone, not Hamburg's 5b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Hamburg
Pull a site-specific report for your exact address in Hamburg, Iowa — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Hamburg averages can't show:
We read public map data around Hamburg — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Hamburg average
How we know this about Hamburg
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this city’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Hamburg’s own record; boundaries and acreage from US Census TIGER/Line 2025; the contamination records from the federal sources named in their beats above. Soil is not read at city grain anywhere on this page — there is no city-resolution survey in our data, which is why you will find no soil grid here rather than a statewide one wearing a local label. The resolution ledger below names every figure this page inherited.
Common questions about Hamburg
When does frost risk typically end in Hamburg?
The last hard freeze (28°F) in Hamburg typically lands around Apr 6, per NOAA 1991–2020 climate normals — earlier than the light-frost dates most charts quote. That marks the hard freeze, not the last light frost — lighter frosts keep biting past it, which is why tender transplants here wait until about Apr 27.
When is the first frost in Hamburg?
The first hard freeze (28°F) in Hamburg typically arrives around Oct 26, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 12, so the watching starts about Sep 26 — about 203 days after the spring freeze cleared.
How long is the growing season in Hamburg?
Measured between 28°F hard freezes, Hamburg sees about 203 frost-free days — roughly Apr 6 through Oct 26, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 27 to Oct 12, about 168 days.
Is the soil safe to grow vegetables in Hamburg?
The federal record around Hamburg is a meaningful one — 74 documented sites, mostly Underground Storage Tanks entries (39), the nearest Underground Storage Tanks record under a tenth of a mile out — so a soil test before new food beds is a sensible precaution here, not a reason to hold back from growing. Remember that proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what sits where.
How do I protect my plants from frost in Hamburg?
From about Sep 26 the job here turns from planting to protecting — the last start even a 30-day crop can finish. As the season closes around the first 28°F hard freeze near Oct 26 (NOAA 1991–2020 climate normals), three moves buy time: row cover or an old sheet over tender plants on still, clear nights; water the soil the afternoon before a freeze, so it holds warmth overnight; and harvest tomatoes, peppers and basil before Oct 26. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Hamburg's scale — its 5b band and its 203-day season. Your yard writes its own version of Hamburg's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
What this page reads at Hamburg’s own scale
6 of the readings below were taken at Hamburg's own scale — its own ~203-day season between 28°F freezes, the 958 acres it covers and 74 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Hamburg's own USDA hardiness band, zones 5bUSDA PHZM 2023
- Hamburg's own 28°F hard-freeze dates, about Apr 6 and Oct 26 and the ~203-day span between themNOAA 1991–2020 Climate Normals
- 74 documented contamination sites on the federal record near Hamburg, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- Hamburg's boundary and the 958 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5b and a ~203-day seasonGrowable Ground crop-matching engine
- The ecoregion at Hamburg's own centroid, the Western Corn Belt PlainsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Hamburg's 958 acres read through its county's SSURGO summaryfrom Fremont County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Fremont County
- The growing challenges every Iowa grower plans around — written at state scale, so they stay on the state guidefrom Iowa
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Fremont County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Hamburg's 958 acreswhy one lot differs from the next →
- Which side of Hamburg you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 958 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record under a tenth of a mile out, measured from the town centrehow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — measured at your address, and averaged away by any Hamburg-wide figureread your own land →
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