When to plant in Piedmont, CA
USDA Zone 10aHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Piedmont, California — all computed from Piedmont's nearest NOAA weather station.
A ~-2-day frost-free window makes Piedmont a short-season garden: choose early varieties and start long-season crops indoors well ahead of the last frost. Zone 10a is warm enough that Piedmont can grow subtropical perennials, and the short (or absent) frost period barely limits the annual calendar.
Frost probability
BERKELEY · 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 Piedmont’s own odds, recorded at BERKELEY.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Mar 20 | Feb 5 | Dec 29 | Nov 27 | Dec 19 | Jan 26 |
| 32°F | Feb 14 | Jan 3 | Dec 14 | Dec 10 | Jan 1 | Jan 29 |
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 Piedmont, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 17 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.
Piedmont planting FAQ
When is the last spring frost in Piedmont, CA?
Piedmont's average last spring frost falls near January 3 — 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 Piedmont, CA?
In Piedmont, the first 32°F freeze of fall lands around January 1 on average. Time your last harvests and any season-extension cover before it.
What hardiness zone is Piedmont in?
Piedmont is in USDA hardiness zone 10a. In zone 10a, winters are mild — many tender perennials overwinter here.
How long is the growing season in Piedmont?
There are roughly -2 frost-free days in Piedmont (a short growing season), running from the average last frost around January 3 to the first fall frost near January 1.
When should I plant tomatoes in Piedmont?
In Piedmont, start tomato seeds indoors around November 8–November 22, then transplant seedlings outdoors around January 10 once the danger of frost has passed.
Never miss a window in Piedmont
An email when it’s time to start seeds, transplant, and sow — timed to Piedmont’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reachFrost dates recorded at BERKELEY, 6 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 Piedmont, CA — Frost Dates & Zone 10a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00040693. Retrieved from https://blissgarden.com/california/piedmont.