When to plant in Oroville, CA
USDA Zone 9bEverything below — frost dates, hardiness zone, and what to plant when in Oroville, California — is derived from the closest NOAA station with complete climate normals.
With about 317 frost-free days, Oroville supports back-to-back plantings; stagger sowings every few weeks to keep beds productive spring through fall. In zone 9b, frost is a minor factor for Oroville — most perennials thrive, and annual vegetables can go out early and stay late.
The average last spring frost in Oroville is now 8 days earlier than in the 1981–2010 normals. See how frost dates are shifting nationwide →
Frost probability
OROVILLE · 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 Oroville’s own odds, recorded at OROVILLE.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Apr 17 | Mar 8 | Feb 3 | Nov 8 | Nov 27 | Dec 18 |
| 32°F | Mar 3 | Jan 30 | Dec 26 | Nov 21 | Dec 13 | Jan 11 |
| 28°F | Feb 4 | Jan 5 | Dec 14 | Dec 5 | Dec 25 | Jan 25 |
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 Oroville, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 29 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.
Oroville planting FAQ
When is the last spring frost in Oroville, CA?
On average, the last spring frost in Oroville is around January 30 (50% probability at 32°F, from 1991–2020 NOAA normals). Wait until after this date to set out tender plants like tomatoes and peppers.
When is the first fall frost in Oroville, CA?
In Oroville, the first 32°F freeze of fall lands around December 13 on average. Time your last harvests and any season-extension cover before it.
What hardiness zone is Oroville in?
Oroville is in USDA hardiness zone 9b. In zone 9b, winters are mild — many tender perennials overwinter here.
How long is the growing season in Oroville?
Oroville has about 317 frost-free days — a long growing season — between the average last spring frost (January 30) and first fall frost (December 13).
When should I plant tomatoes in Oroville?
For Oroville, sow tomatoes indoors about December 5–December 19 and move the seedlings out around February 6, after the last spring frost.
Never miss a window in Oroville
An email when it’s time to start seeds, transplant, and sow — timed to Oroville’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Chico · 37 km
- Marysville · 38 km
- Yuba City · 41 km
- Linda · 41 km
- Olivehurst · 46 km
- Grass Valley · 53 km
- Lincoln · 73 km
- North Auburn · 75 km
Frost dates recorded at OROVILLE, 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 Oroville, CA — Frost Dates & Zone 9b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00046521. Retrieved from https://blissgarden.com/california/oroville.