Rio Vista, California, sits in USDA hardiness zone 9b — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
Growers here do well with okra, meyer lemon, california poppy, and artichoke — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.
Even in Rio Vista, 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 Rio Vista 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 Rio Vista — soil, climate, flood, and parcel records. How we handle your address.
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Rio Vista — the short answer
Rio Vista, California: USDA zone 9b, about 335 days between hard freezes, across 4K acres of city.
- USDA zone
- 9b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Jan 15
- Solano County normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Dec 16
- Solano County normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~335
- Solano County normal — NOAA 1991–2020, nearest to this town
- City area
- 4K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. No 30-year normal resolves at this town’s own centroid, so the hard-freeze dates are Solano County’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 9b is Rio Vista's average, not your lot's — a low corner or a tree line moves it. Against Rio Vista's 335-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Rio Vista
Each reading below is measured for Rio Vista itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsRio Vista runs about 335 days between hard freezes (read from Solano County, the closest normal to Rio Vista) — close to year-round growing.
Frost is rarely the limit here; winter plantings are as real as summer ones, and the harder question is which crops shrug off the summer heat.
Grow cool-season crops through the mild winter, and choose heat-tolerant varieties for the summer beds.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredRio Vista sits in USDA hardiness zone 9b.
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 Rio Vista is in
Rio Vista sits in the Central California Foothills and Coastal Mountains — EPA Level III, inside the wider Mediterranean California. That is read at Rio Vista's own centroid, and it is not what its county reads: Solano County is mostly Central California Valley. The wider page above you is answering a different question about different ground.
What Grows in Rio Vista
Every plant below cleared Rio Vista's own zone 9b and its 335-day season. Each card opens that plant's California profile. How we score.
Is it too late to plant in Rio Vista?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Jan 1; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Jan 15 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 16 — long-season crops need about 90 days of runway, quick greens only 30. And with a calendar this mild, the honest answer is that planting barely stops — winter opens seasons colder regions never see.
What's on the federal record near Rio Vista
Closest first, within ~10 miles of Rio Vista. Listing isn't leaking, and distance isn't exposure.
- PG&E MARKS COMPRESSOR STATIONBrownfields · 500 ft
- ARB INCBrownfields · 950 ft
- EVI WEATHERFORD CORPORATIONBrownfields · 1000 ft
- PG&E COMPRESSOR #17Brownfields · 2000 ft
- SUTTER HOME WINERY INCBrownfields · 2300 ft
- GOMES WARREN E EXCAVATING INCBrownfields · 2500 ft
- PAUL GRAHAM DRILLINGBrownfields · 0.5 mi
- CITY OF RIO VISTA NORTHWEST WASTEWATER TREATMENT PLANTBrownfields · 0.7 mi
- TRANSPORTATION CONCEPTSBrownfields · 0.7 mi
- MORENO TRENCHINGBrownfields · 0.7 mi
- WARRIOR GOLF VENTURE LLC DBA THE GOLF AT RIO VISTABrownfields · 0.8 mi
- MAXX FOR LESS INC.Brownfields · 0.9 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Rio Vista'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 Rio Vista.
Total Sites
211
within ~10 miles of Rio Vista
Risk Level
Elevated
Highest-severity
1 Toxics Release Inventory facility
Sources Checked
within ~10 miles of Rio Vista
Severity Distribution
within ~10 miles of Rio Vista
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Rio Vista, Brownfields runs higher than the national average — 184 sites within ~10 miles of Rio Vista. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Brownfields: Brownfield sites are former commercial or industrial properties where legacy soil contamination (heavy metals, PAHs, petroleum compounds) may persist.
Check EPA brownfield remediation status — many sites have completed cleanup with institutional controls.
Check your specific parcel in Rio Vista
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 Rio Vista average
Your land is one point inside Rio Vista
Everything above resolves to Rio Vista as a whole — one PHZM band, read across 4K acres, with hard-freeze dates borrowed from Solano County’s record because no 30-year normal resolves at this city’s own centroid. 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 Rio Vista Average
Rio Vista Average
- ●USDA Zones 9b, averaged across Rio Vista
- ●One soil character for all of Rio Vista
- ●Frost dates read at Rio Vista's scale: Jan 15 to Dec 16
YOUR Parcel
- ✓Your exact zone, not Rio Vista's 9b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Rio Vista
Pull a site-specific report for your exact address in Rio Vista, California — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Rio Vista averages can't show:
We read public map data around Rio Vista — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Rio Vista average
How we know this about Rio Vista
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 Solano County’s record, because none resolves here; 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 Rio Vista
When does frost risk typically end in Rio Vista?
The last hard freeze (28°F) in Rio Vista typically lands around Jan 15, 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 Feb 5.
When is the first frost in Rio Vista?
The first hard freeze (28°F) in Rio Vista typically arrives around Dec 16, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Dec 2, so the watching starts about Nov 16 — about 335 days after the spring freeze cleared.
How long is the growing season in Rio Vista?
Measured between 28°F hard freezes, Rio Vista sees about 335 frost-free days — roughly Jan 15 through Dec 16, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Feb 5 to Dec 2, about 300 days.
Is the soil safe to grow vegetables in Rio Vista?
The federal record around Rio Vista is a meaningful one — 211 documented sites, mostly Brownfields entries (184), the nearest Brownfields 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 Rio Vista?
From about Nov 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 Dec 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 Dec 16. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Rio Vista's scale — its 9b band and its 335-day season. Your yard writes its own version of Rio Vista'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 Rio Vista’s own scale
5 of the readings below were taken at Rio Vista's own scale — the 4,224 acres it covers and 211 documented sites around it; 5 are borrowed from a wider read, named and linked below.
Measured here
- Rio Vista's own USDA hardiness band, zones 9bUSDA PHZM 2023
- 211 documented contamination sites on the federal record near Rio Vista, the closest Brownfields record under a tenth of a mile out from the town centreFederal environmental registers
- Rio Vista's boundary and the 4,224 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 9b and a ~335-day seasonGrowable Ground crop-matching engine
- Rio Vista sits in the Central California Foothills and Coastal Mountains — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
Inherited from a wider read
- The 28°F hard-freeze dates — Rio Vista has no normal of its own, so its county's is the closest measured readfrom Solano County
- Soil character — no town-scale survey exists, so Rio Vista's 4,224 acres read through its county's SSURGO summaryfrom Solano County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Solano County
- The growing challenges every California grower plans around — written at state scale, so they stay on the state guidefrom California
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Solano County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Rio Vista's 4,224 acreswhy one lot differs from the next →
- Which side of Rio Vista you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 4,224 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields 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 Rio Vista-wide figureread your own land →
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