Westerly, Rhode Island, sits in USDA hardiness zone 7a — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
The conditions favor cabbage, hazelnut, california poppy, and collard greens, among others — though every individual site edits that list with its own soil, sun, and drainage.
Even in Westerly, 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 Westerly 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 Westerly — soil, climate, flood, and parcel records. How we handle your address.
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Westerly — the short answer
Westerly, Rhode Island: USDA zone 7a, about 224 days between hard freezes, across 10K acres of town.
- USDA zone
- 7a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 31
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 10
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~224
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 10K 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 Westerly's average, not your lot's — a low corner or a tree line moves it. Against Westerly's 224-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Westerly
Each reading below is measured for Westerly itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredWesterly runs about 224 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
MeasuredWesterly 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 Westerly is in
Westerly sits in the Northeastern Coastal Zone — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Westerly's own centroid rather than borrowed from Washington County.
What Grows in Westerly
Every plant below cleared Westerly's own zone 7a and its 224-day season. Each card opens that plant's Rhode Island profile. How we score.
Is it too late to plant in Westerly?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Mar 3; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 31 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 10 — long-season crops need about 90 days of runway, quick greens only 30. A long window like this one runs successions deep into fall — and even its last weeks take quick greens and garlic.
Documented around Westerly
Spotted lanternfly documented 19 miles from Westerly, first recorded 2022. What to watch for.
What's on the federal record near Westerly
Closest first, within ~10 miles of Westerly. Listing isn't leaking, and distance isn't exposure.
- THE NARRAGANSETT ELECTRIC COMPANYBrownfields · 1400 ft
- M.J. MURPHY, INC.Underground Storage Tanks · 1700 ft
- BABCOCK VILLAGEUnderground Storage Tanks · 2100 ft
- AUTOWORKSBrownfields · 2100 ft
- CHERENZIA EXCAVATION INCBrownfields · 0.5 mi
- IN MOTION MARINE REPAIRBrownfields · 0.5 mi
- PATS AUTO CENTERBrownfields · 0.5 mi
- NARRAGANSETT AUTO BODYBrownfields · 0.6 mi
- SHETUCKET PLUMBING SUPPLY COMPANY, INC.Underground Storage Tanks · 0.6 mi
- HOXSIE BUICK-PONTIAC INC.Underground Storage Tanks · 0.7 mi
- FAMILY DOLLAR #2289Brownfields · 0.7 mi
- GRANITE STREET SUNOCOUnderground Storage Tanks · 0.7 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Westerly'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 Westerly.
Total Sites
631
within ~10 miles of Westerly
Risk Level
Elevated
Highest-severity
7 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Westerly
Severity Distribution
within ~10 miles of Westerly
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Westerly, Nitrate runs higher than the national average — 218 sites within ~10 miles of Westerly. That's not a problem with your land — it's information about it.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Westerly
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 Westerly average
Your land is one point inside Westerly
Everything above resolves to Westerly as a whole — one PHZM band and one 28°F frost record, read across 10K 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 Westerly Average
Westerly Average
- ●USDA Zones 7a, averaged across Westerly
- ●One soil character for all of Westerly
- ●Frost dates read at Westerly's scale: Mar 31 to Nov 10
YOUR Parcel
- ✓Your exact zone, not Westerly's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Westerly
Pull a site-specific report for your exact address in Westerly, Rhode Island — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Westerly averages can't show:
We read public map data around Westerly — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Westerly average
How we know this about Westerly
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 Westerly’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 Westerly
When does frost risk typically end in Westerly?
The last hard freeze (28°F) in Westerly typically lands around Mar 31, 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 21.
When is the first frost in Westerly?
The first hard freeze (28°F) in Westerly typically arrives around Nov 10, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 27, so the watching starts about Oct 11 — about 224 days after the spring freeze cleared.
How long is the growing season in Westerly?
Measured between 28°F hard freezes, Westerly sees about 224 frost-free days — roughly Mar 31 through Nov 10, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 21 to Oct 27, about 189 days.
Is the soil safe to grow vegetables in Westerly?
The federal record around Westerly is a meaningful one — 631 documented sites, mostly Underground Storage Tanks entries (232), the nearest Brownfields record about 0.3 miles 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 Westerly?
From about Oct 11 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 Nov 10 (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 Nov 10. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Westerly's scale — its 7a band and its 224-day season. Your yard writes its own version of Westerly'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 Westerly’s own scale
7 of the readings below were taken at Westerly's own scale — its own ~224-day season between 28°F freezes, the 10,134 acres it covers and 631 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Westerly's own USDA hardiness band, zones 7aUSDA PHZM 2023
- Westerly's own 28°F hard-freeze dates, about Mar 31 and Nov 10 and the ~224-day span between themNOAA 1991–2020 Climate Normals
- 631 documented contamination sites on the federal record near Westerly, the closest Brownfields record about 0.3 miles out from the town centreFederal environmental registers
- Westerly's boundary and the 10,134 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~224-day seasonGrowable Ground crop-matching engine
- The ecoregion at Westerly's own centroid, the Northeastern Coastal ZoneUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Westerlylydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Westerly's 10,134 acres read through its county's SSURGO summaryfrom Washington County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Washington County
- The growing challenges every Rhode Island grower plans around — written at state scale, so they stay on the state guidefrom Rhode Island
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Washington County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Westerly's 10,134 acreswhy one lot differs from the next →
- Which side of Westerly you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 10,134 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 0.3 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 Westerly-wide figureread your own land →
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