When to plant in Fountain Valley, CA
USDA Zone 10bFountain Valley, California frost dates, USDA zone, and a full-year planting calendar, drawn from the nearest NOAA station and tuned to the local season.
With about 354 frost-free days, Fountain Valley supports back-to-back plantings; stagger sowings every few weeks to keep beds productive spring through fall. These dates come from a station roughly 18 km away, the closest with full normals; terrain around Fountain Valley (elevation, water, pavement) can move your real frost dates a few days either way. In zone 10b, frost is a minor factor for Fountain Valley — most perennials thrive, and annual vegetables can go out early and stay late.
Frost probability
TUSTIN IRVINE RCH · 1991–2020The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Fountain Valley’s own odds, recorded at TUSTIN IRVINE RCH.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Mar 5 | Feb 1 | Jan 3 | Nov 24 | Dec 13 | Jan 8 |
| 32°F | Feb 2 | Jan 5 | Dec 14 | Dec 3 | Dec 25 | Jan 20 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Nothing new to sow or transplant outdoors in the next few weeks — a seasonal lull. Check the full-year calendar below for the next window.
Full-year planting calendar
Each bar is the exact window to take a planting action in Fountain Valley, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 37 km · complete 32°F normalsWhen stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.
Fountain Valley planting FAQ
When is the last spring frost in Fountain Valley, CA?
Fountain Valley's average last spring frost falls near January 5 — the 50% mark at 32°F in the 1991–2020 normals. Hold tender transplants until the risk has passed, then plant out.
When is the first fall frost in Fountain Valley, CA?
The first fall frost in Fountain Valley typically arrives around December 25 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.
What hardiness zone is Fountain Valley in?
Fountain Valley is in USDA hardiness zone 10b. In zone 10b, winters are mild — many tender perennials overwinter here.
How long is the growing season in Fountain Valley?
Fountain Valley has about 354 frost-free days — a long growing season — between the average last spring frost (January 5) and first fall frost (December 25).
When should I plant tomatoes in Fountain Valley?
For Fountain Valley, sow tomatoes indoors about November 10–November 24 and move the seedlings out around January 12, after the last spring frost.
Never miss a window in Fountain Valley
An email when it’s time to start seeds, transplant, and sow — timed to Fountain Valley’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Huntington Beach · 5 km
- Westminster · 6 km
- Costa Mesa · 6 km
- Santa Ana · 7 km
- Garden Grove · 8 km
- Stanton · 11 km
- Orange · 12 km
- Seal Beach · 12 km
Frost dates recorded at TUSTIN IRVINE RCH, 18 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.
BlissGarden. "When to Plant in Fountain Valley, CA — Frost Dates & Zone 10b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00049087. Retrieved from https://blissgarden.com/california/fountain-valley.