When to plant in Atascadero, CA
USDA Zone 9aAtascadero, California frost dates, USDA zone, and a full-year planting calendar, drawn from the nearest NOAA station and tuned to the local season.
Atascadero's nearest full-normals station sits about 16 km out, so treat these as a close estimate — local microclimate can nudge your first and last frost. Zone 9a is warm enough that Atascadero can grow subtropical perennials, and the short (or absent) frost period barely limits the annual calendar.
The average last spring frost in Atascadero is now 12 days earlier than in the 1981–2010 normals. See how frost dates are shifting nationwide →
Frost probability
PASO ROBLES · 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 Atascadero’s own odds, recorded at PASO ROBLES.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 6 | Apr 18 | Mar 24 | Oct 12 | Oct 27 | Nov 12 |
| 32°F | Apr 13 | Mar 15 | Feb 12 | Oct 23 | Nov 10 | Nov 29 |
| 28°F | Mar 4 | Feb 9 | Jan 2 | Nov 4 | Nov 26 | Dec 19 |
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 Atascadero, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 20 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.
Atascadero planting FAQ
When is the last spring frost in Atascadero, CA?
Plan for the last spring frost in Atascadero around March 15 (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 Atascadero, CA?
In Atascadero, the first 32°F freeze of fall lands around November 10 on average. Time your last harvests and any season-extension cover before it.
What hardiness zone is Atascadero in?
Atascadero is in USDA hardiness zone 9a. In zone 9a, winters are mild — many tender perennials overwinter here.
How long is the growing season in Atascadero?
There are roughly 240 frost-free days in Atascadero (a long growing season), running from the average last frost around March 15 to the first fall frost near November 10.
When should I plant tomatoes in Atascadero?
In Atascadero, start tomato seeds indoors around January 18–February 1, then transplant seedlings outdoors around March 22 once the danger of frost has passed.
Never miss a window in Atascadero
An email when it’s time to start seeds, transplant, and sow — timed to Atascadero’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- El Paso de Robles (Paso Robles) · 16 km
- Morro Bay · 21 km
- Los Osos · 23 km
- San Luis Obispo · 24 km
- Grover Beach · 41 km
- Arroyo Grande · 41 km
- Nipomo · 53 km
- Santa Maria · 65 km
Frost dates recorded at PASO ROBLES, 16 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 Atascadero, CA — Frost Dates & Zone 9a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00046730. Retrieved from https://blissgarden.com/california/atascadero.