When to plant in San Luis Obispo, CA
USDA Zone 9bEverything below — frost dates, hardiness zone, and what to plant when in San Luis Obispo, California — is derived from the closest NOAA station with complete climate normals.
A generous ~314-day season lets San Luis Obispo gardeners direct-sow more and still ripen long-maturity crops like melons and winter squash. In zone 9b, frost is a minor factor for San Luis Obispo — most perennials thrive, and annual vegetables can go out early and stay late.
Frost probability
SAN LUIS OBISPO AP · 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 San Luis Obispo’s own odds, recorded at SAN LUIS OBISPO AP.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Apr 16 | Mar 17 | Feb 6 | Nov 3 | Nov 24 | Dec 11 |
| 32°F | Mar 7 | Jan 31 | Dec 23 | Nov 20 | Dec 11 | Jan 13 |
| 28°F | Feb 1 | Jan 3 | Dec 11 | Dec 4 | Dec 28 | Jan 26 |
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 San Luis Obispo, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 12 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.
San Luis Obispo planting FAQ
When is the last spring frost in San Luis Obispo, CA?
Plan for the last spring frost in San Luis Obispo around January 31 (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 San Luis Obispo, CA?
Expect San Luis Obispo's first fall frost near December 11 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.
What hardiness zone is San Luis Obispo in?
San Luis Obispo is in USDA hardiness zone 9b. In zone 9b, winters are mild — many tender perennials overwinter here.
How long is the growing season in San Luis Obispo?
San Luis Obispo has about 314 frost-free days — a long growing season — between the average last spring frost (January 31) and first fall frost (December 11).
When should I plant tomatoes in San Luis Obispo?
For San Luis Obispo, sow tomatoes indoors about December 6–December 20 and move the seedlings out around February 7, after the last spring frost.
Never miss a window in San Luis Obispo
An email when it’s time to start seeds, transplant, and sow — timed to San Luis Obispo’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Los Osos · 15 km
- Grover Beach · 17 km
- Arroyo Grande · 18 km
- Morro Bay · 21 km
- Atascadero · 24 km
- Nipomo · 30 km
- El Paso de Robles (Paso Robles) · 40 km
- Santa Maria · 42 km
Frost dates recorded at SAN LUIS OBISPO AP, 4 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 San Luis Obispo, CA — Frost Dates & Zone 9b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00093206. Retrieved from https://blissgarden.com/california/san-luis-obispo.