When to plant in Irvine, CA
USDA Zone 10aHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Irvine, California — all computed from Irvine's nearest NOAA weather station.
A generous ~354-day season lets Irvine gardeners direct-sow more and still ripen long-maturity crops like melons and winter squash. Zone 10a is warm enough that Irvine can grow subtropical perennials, and the short (or absent) frost period barely limits the annual calendar.
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 Irvine’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 Irvine, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 35 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.
Irvine planting FAQ
When is the last spring frost in Irvine, CA?
Plan for the last spring frost in Irvine around January 5 (the date it has a 50% chance of a 32°F freeze). Anything frost-sensitive should go out after it.
When is the first fall frost in Irvine, CA?
The first fall frost in Irvine typically arrives around December 25 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.
What hardiness zone is Irvine in?
Irvine is in USDA hardiness zone 10a. In zone 10a, winters are mild — many tender perennials overwinter here.
How long is the growing season in Irvine?
There are roughly 354 frost-free days in Irvine (a long growing season), running from the average last frost around January 5 to the first fall frost near December 25.
When should I plant tomatoes in Irvine?
In Irvine, start tomato seeds indoors around November 10–November 24, then transplant seedlings outdoors around January 12 once the danger of frost has passed.
Never miss a window in Irvine
An email when it’s time to start seeds, transplant, and sow — timed to Irvine’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Tustin · 7 km
- Laguna Woods · 8 km
- Lake Forest · 9 km
- North Tustin · 10 km
- Newport Beach · 10 km
- Aliso Viejo · 12 km
- Laguna Hills · 12 km
- Santa Ana · 12 km
Frost dates recorded at TUSTIN IRVINE RCH, 3 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 Irvine, CA — Frost Dates & Zone 10a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00049087. Retrieved from https://blissgarden.com/california/irvine.