Williams, Arizona, sits in USDA hardiness zone 7a — a zone band wide enough that plant choice, not possibility, is the interesting question.
A short list that earns its place here — cabbage, blackberry, california poppy, and collard greens — with any one site's soil, sun, and drainage making the final cut.
Even in Williams, 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 Williams 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 Williams — soil, climate, flood, and parcel records. How we handle your address.
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Williams — the short answer
Williams, Arizona: USDA zone 7a, about 159 days between hard freezes, across 28K acres of city.
- USDA zone
- 7a
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 10
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 16
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~159
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 28K 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 7a is Williams's average, not your lot's — a low corner or a tree line moves it. Against Williams's 159-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Williams
Each reading below is measured for Williams itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredWilliams runs about 159 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
MeasuredWilliams sits in USDA hardiness zone 7a.
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 Williams is in
Williams sits in the Arizona/New Mexico Mountains — EPA Level III, inside the wider Temperate Sierras. That is read at Williams's own centroid, and it is not what its county reads: Coconino County is mostly Arizona/New Mexico Plateau. The wider page above you is answering a different question about different ground.
What Grows in Williams
Every plant below cleared Williams's own zone 7a and its 159-day season. Each card opens that plant's Arizona profile. How we score.
Is it too late to plant in Williams?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Apr 12; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 10 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 16 — long-season crops need about 90 days of runway, quick greens only 30. Even past midsummer there is room for a true fall garden here, and garlic planted near the close carries the momentum into next year.
Documented around Williams
Survey cells within 31 miles of Williams checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 320 miles off. What to watch for.
What's on the federal record near Williams
Closest first, within ~10 miles of Williams. Listing isn't leaking, and distance isn't exposure.
- M & M OIL CO INCUnderground Storage Tanks · 1900 ft
- BLUE RIBBON AUTOMOTIVEUnderground Storage Tanks · 2000 ft
- WILLIAMS CO #128531Underground Storage Tanks · 2000 ft
- OPAL L MEANSUnderground Storage Tanks · 2000 ft
- G & M TIRESUnderground Storage Tanks · 2000 ft
- SOUTH RIM WINE & BEER GARAGEUnderground Storage Tanks · 2000 ft
- TWISTERS 50S SODA FOUNTAINUnderground Storage Tanks · 2100 ft
- HIGH COUNTRY MARKETUnderground Storage Tanks · 2100 ft
- OLSON BROTHERSUnderground Storage Tanks · 2100 ft
- WILLIAMS AUTO SUPPLYUnderground Storage Tanks · 2100 ft
- HANK'S TIRESUnderground Storage Tanks · 2100 ft
- MARSHALL BENNETTUnderground Storage Tanks · 2100 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Williams'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 Williams.
Total Sites
67
within ~10 miles of Williams
Risk Level
Moderate
Highest-severity
1 Toxics Release Inventory facility
Sources Checked
within ~10 miles of Williams
Severity Distribution
within ~10 miles of Williams
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Williams, Underground Storage Tanks runs higher than the national average — 47 sites within ~10 miles of Williams. That's not a problem with your land — it's information about it.
Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.
Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
Check your specific parcel in Williams
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 Williams average
Your land is one point inside Williams
Everything above resolves to Williams as a whole — one PHZM band and one 28°F frost record, read across 28K 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 Williams Average
Williams Average
- ●USDA Zones 7a, averaged across Williams
- ●One soil character for all of Williams
- ●Frost dates read at Williams's scale: May 10 to Oct 16
YOUR Parcel
- ✓Your exact zone, not Williams's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Williams
Pull a site-specific report for your exact address in Williams, Arizona — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Williams averages can't show:
We read public map data around Williams — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Williams average
How we know this about Williams
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 Williams’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 Williams
When does frost risk typically end in Williams?
The last hard freeze (28°F) in Williams typically lands around May 10, 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 31.
When is the first frost in Williams?
The first hard freeze (28°F) in Williams typically arrives around Oct 16, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 2, so the watching starts about Sep 16 — about 159 days after the spring freeze cleared.
How long is the growing season in Williams?
Measured between 28°F hard freezes, Williams sees about 159 frost-free days — roughly May 10 through Oct 16, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 31 to Oct 2, about 124 days.
Is the soil safe to grow vegetables in Williams?
The federal record around Williams shows 67 documented sites, mostly Underground Storage Tanks entries (47), the nearest Underground Storage Tanks record about 0.4 miles out — a typical footprint for a growing area, and proximity to a documented site is information, not a diagnosis of any one yard. It's worth seeing which recorded sites sit closest to where you grow, and testing the soil before new food beds near any of them.
How do I protect my plants from frost in Williams?
From about Sep 16 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 16 (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 16. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Williams's scale — its 7a band and its 159-day season. Your yard writes its own version of Williams'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 Williams’s own scale
7 of the readings below were taken at Williams's own scale — its own ~159-day season between 28°F freezes, the 28,051 acres it covers and 67 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Williams's own USDA hardiness band, zones 7aUSDA PHZM 2023
- Williams's own 28°F hard-freeze dates, about May 10 and Oct 16 and the ~159-day span between themNOAA 1991–2020 Climate Normals
- 67 documented contamination sites on the federal record near Williams, the closest Underground Storage Tanks record about 0.4 miles out from the town centreFederal environmental registers
- Williams's boundary and the 28,051 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~159-day seasonGrowable Ground crop-matching engine
- Williams sits in the Arizona/New Mexico Mountains — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
- Lanternfly survey cells around Williams checked, none carrying a detectionlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Williams's 28,051 acres read through its county's SSURGO summaryfrom Coconino County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Coconino County
- The growing challenges every Arizona grower plans around — written at state scale, so they stay on the state guidefrom Arizona
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Coconino County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Williams's 28,051 acreswhy one lot differs from the next →
- Which side of Williams you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 28,051 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.4 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 Williams-wide figureread your own land →