Fairmount, Colorado, sits in USDA hardiness zone 6a — a zone band wide enough that plant choice, not possibility, is the interesting question.
The conditions favor cabbage, hazelnut, lavender, and collard greens, among others — though every individual site edits that list with its own soil, sun, and drainage.
Even in Fairmount, 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 Fairmount 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 Fairmount — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Fairmount — the short answer
Fairmount, Colorado: USDA zone 6a, about 182 days between hard freezes, across 4K acres of town.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 21
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 20
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~182
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 4K 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 6a is Fairmount's average, not your lot's — a low corner or a tree line moves it. Against Fairmount's 182-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Fairmount
Each reading below is measured for Fairmount itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredFairmount runs about 182 days between hard freezes — a moderate growing season.
There is room for the full run of cool-season crops plus a warm-season main crop, but the calendar is tight enough that a late spring or early fall frost still decides how much finishes.
Time warm-season transplants to your last hard freeze, and a few weeks of season extension turns a near-miss harvest into a sure one.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredFairmount sits in USDA hardiness zone 6a.
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 Fairmount is in
Fairmount sits in the High Plains — EPA Level III, inside the wider Great Plains. That is read at Fairmount's own centroid, and it is not what its county reads: Jefferson County is mostly Southern Rockies. The wider page above you is answering a different question about different ground.
What Grows in Fairmount
Every plant below cleared Fairmount's own zone 6a and its 182-day season. Each card opens that plant's Colorado profile. How we score.
Is it too late to plant in Fairmount?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Mar 24; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 21 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 20 — long-season crops need about 90 days of runway, quick greens only 30. Late in the year the fall bench takes over — quick greens, radishes, and garlic that repays you next summer.
What's on the federal record near Fairmount
Closest first, within ~10 miles of Fairmount. Listing isn't leaking, and distance isn't exposure.
- SC00307013BDA USGS 394734105102901Nitrate · 1100 ft
- Jack FarnhamUnderground Storage Tanks · 0.6 mi
- STENTECH PHOTO STENCIL, LLC - 16080 TABLBrownfields · 0.7 mi
- COORSTEKBrownfields · 0.7 mi
- COLORADO SCHOOL OF MINES RESEARCH INSTSuperfund · 0.7 mi
- Fairmount Fire Protection DistUnderground Storage Tanks · 0.7 mi
- FAIRMOUNT FIRE DEPARTMENTBrownfields · 0.7 mi
- TDA RESEARCH INCBrownfields · 0.8 mi
- COORS BREWING COMPANY ENDLINE BUILDINGToxics Release Inventory · 0.8 mi
- CHRONOPOL INCToxics Release Inventory · 0.9 mi
- ACCULABS RESEARCH INCORPORATEDBrownfields · 0.9 mi
- HAZEN RESEARCH INCBrownfields · 0.9 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Fairmount'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 Fairmount.
Sources Checked
within ~10 miles of Fairmount
Severity Distribution
within ~10 miles of Fairmount
Highest-Severity Sites
Know Before You Grow
- •Underground tanks leak petroleum as they age — near a former filling station, test the soil.
- •Near a brownfield, raised beds of imported soil give your food clean ground.
- •TRI facilities report what they release. Check the wind — downwind beds catch more of it.
Check your specific parcel in Fairmount
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 Fairmount average
Your land is one point inside Fairmount
Everything above resolves to Fairmount as a whole — one PHZM band and one 28°F frost record, read across 4K 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 town 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 Fairmount Average
Fairmount Average
- ●USDA Zones 6a, averaged across Fairmount
- ●One soil character for all of Fairmount
- ●Frost dates read at Fairmount's scale: Apr 21 to Oct 20
YOUR Parcel
- ✓Your exact zone, not Fairmount's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Fairmount
Pull a site-specific report for your exact address in Fairmount, Colorado — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Fairmount averages can't show:
We read public map data around Fairmount — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Fairmount average
How we know this about Fairmount
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this town’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Fairmount’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 town grain anywhere on this page — there is no town-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 Fairmount
When does frost risk typically end in Fairmount?
The last hard freeze (28°F) in Fairmount typically lands around Apr 21, 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 May 12.
When is the first frost in Fairmount?
The first hard freeze (28°F) in Fairmount typically arrives around Oct 20, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 6, so the watching starts about Sep 20 — about 182 days after the spring freeze cleared.
How long is the growing season in Fairmount?
Measured between 28°F hard freezes, Fairmount sees about 182 frost-free days — roughly Apr 21 through Oct 20, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 12 to Oct 6, about 147 days.
Is the soil safe to grow vegetables in Fairmount?
The federal record around Fairmount runs heavier than most — 2,363 documented sites, mostly Underground Storage Tanks entries (1,347), the nearest Nitrate record about 0.2 miles out — so test the soil before planting food in the ground, and raised beds with clean imported soil grow well in the meantime. Even here, proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what's recorded and where.
How do I protect my plants from frost in Fairmount?
From about Sep 20 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 20 (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 20. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Fairmount's scale — its 6a band and its 182-day season. Your yard writes its own version of Fairmount'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 Fairmount’s own scale
6 of the readings below were taken at Fairmount's own scale — its own ~182-day season between 28°F freezes, the 3,892 acres it covers and 2,363 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Fairmount's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Fairmount's own 28°F hard-freeze dates, about Apr 21 and Oct 20 and the ~182-day span between themNOAA 1991–2020 Climate Normals
- 2,363 documented contamination sites on the federal record near Fairmount, the closest Nitrate record about 0.2 miles out from the town centreFederal environmental registers
- Fairmount's boundary and the 3,892 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~182-day seasonGrowable Ground crop-matching engine
- Fairmount sits in the High Plains — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Fairmount's 3,892 acres read through its county's SSURGO summaryfrom Jefferson County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Jefferson County
- The growing challenges every Colorado grower plans around — written at state scale, so they stay on the state guidefrom Colorado
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Jefferson County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Fairmount's 3,892 acreswhy one lot differs from the next →
- Which side of Fairmount you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 3,892 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate record about 0.2 miles 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 Fairmount-wide figureread your own land →
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