When to plant in Ukiah, CA
USDA Zone 9aHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Ukiah, California — all computed from Ukiah's nearest NOAA weather station.
Ukiah enjoys a long ~246-day frost-free season — you can succession-sow, fit in a second crop, and grow long-season heat-lovers with room to spare. Zone 9a is warm enough that Ukiah can grow subtropical perennials, and the short (or absent) frost period barely limits the annual calendar.
Frost probability
UKIAH · 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 Ukiah’s own odds, recorded at UKIAH.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 9 | Apr 17 | Mar 31 | Oct 18 | Nov 2 | Nov 19 |
| 32°F | Apr 15 | Mar 19 | Feb 13 | Nov 2 | Nov 20 | Dec 9 |
| 28°F | Mar 13 | Feb 6 | Dec 25 | Nov 17 | Dec 5 | Jan 6 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Full-year planting calendar
Each bar is the exact window to take a planting action in Ukiah, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 25 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.
Ukiah planting FAQ
When is the last spring frost in Ukiah, CA?
Plan for the last spring frost in Ukiah around March 19 (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 Ukiah, CA?
Expect Ukiah's first fall frost near November 20 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.
What hardiness zone is Ukiah in?
Ukiah is in USDA hardiness zone 9a. In zone 9a, winters are mild — many tender perennials overwinter here.
How long is the growing season in Ukiah?
There are roughly 246 frost-free days in Ukiah (a long growing season), running from the average last frost around March 19 to the first fall frost near November 20.
When should I plant tomatoes in Ukiah?
In Ukiah, start tomato seeds indoors around January 22–February 5, then transplant seedlings outdoors around March 26 once the danger of frost has passed.
Never miss a window in Ukiah
An email when it’s time to start seeds, transplant, and sow — timed to Ukiah’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Clearlake · 54 km
- Healdsburg · 65 km
- Windsor · 75 km
- Santa Rosa · 89 km
- Rohnert Park · 99 km
- Petaluma · 112 km
- Sonoma · 115 km
- Napa · 123 km
Frost dates recorded at UKIAH, 1 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 Ukiah, CA — Frost Dates & Zone 9a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00049122. Retrieved from https://blissgarden.com/california/ukiah.