When to plant in Pomona, CA
USDA Zone 10aEverything below — frost dates, hardiness zone, and what to plant when in Pomona, California — is derived from the closest NOAA station with complete climate normals.
Pomona enjoys a long ~354-day frost-free season — you can succession-sow, fit in a second crop, and grow long-season heat-lovers with room to spare. In zone 10a, frost is a minor factor for Pomona — most perennials thrive, and annual vegetables can go out early and stay late.
Frost probability
POMONA/FAIRPLEX · 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 Pomona’s own odds, recorded at POMONA/FAIRPLEX.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Mar 9 | Feb 8 | Dec 29 | Nov 21 | Dec 10 | Dec 26 |
| 32°F | Feb 18 | Jan 8 | Dec 14 | Dec 5 | Dec 28 | Feb 2 |
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 Pomona, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 15 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.
Pomona planting FAQ
When is the last spring frost in Pomona, CA?
Plan for the last spring frost in Pomona around January 8 (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 Pomona, CA?
The first fall frost in Pomona typically arrives around December 28 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.
What hardiness zone is Pomona in?
Pomona is in USDA hardiness zone 10a. In zone 10a, winters are mild — many tender perennials overwinter here.
How long is the growing season in Pomona?
Pomona has about 354 frost-free days — a long growing season — between the average last spring frost (January 8) and first fall frost (December 28).
When should I plant tomatoes in Pomona?
For Pomona, sow tomatoes indoors about November 13–November 27 and move the seedlings out around January 15, after the last spring frost.
Never miss a window in Pomona
An email when it’s time to start seeds, transplant, and sow — timed to Pomona’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reachFrost dates recorded at POMONA/FAIRPLEX, 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 Pomona, CA — Frost Dates & Zone 10a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00047050. Retrieved from https://blissgarden.com/california/pomona.