Frost dates for San Luis Obispo, CA
When the last spring frost and first fall frost usually come, and when to plant, from 30 years of NOAA weather records.
Last spring frost
January 31
typical year
Safe to plant
March 7
frost is over in 9 of 10 years
First fall frost
December 11
typical year
Growing season
319 days
frost-free, typical year
Frost watch this week
Tonight's and the next six nights' lows from the National Weather Service forecast for the station's location. Frost: 32°F or colder. Possible frost: 33–36°F, mostly in low spots on clear, still nights.
When to plant
Counted from this page's frost dates. Warm-season crops wait for the safe-to-plant date.
| Crop | Start indoors | Plant outside | Fall planting |
|---|---|---|---|
| Cool-season crops | |||
| Peas | – | Jan 3 – 17 | – |
| Spinach | – | Dec 20 – Jan 10 | Oct 16 – 30 |
| Lettuce | – | Jan 3 – 24 | Oct 16 – 30 |
| Radishes | – | Jan 3 – Feb 14 | Oct 30 – Nov 13 |
| Onions | – | Jan 3 – 17 | – |
| Potatoes | – | Jan 10 – 24 | – |
| Carrots | – | Jan 10 – 31 | Sep 18 – Oct 2 |
| Beets | – | Jan 3 – 17 | Oct 2 – 16 |
| Kale | Nov 22 – Dec 6 | Jan 3 – 17 | Oct 2 – 16 |
| Broccoli | Nov 22 – Dec 6 | Jan 17 – 31 | Oct 2 – 16 |
| Cabbage | Nov 8 – 22 | Jan 3 – 17 | Oct 2 – 16 |
| Garlic | – | – | Oct 30 – Nov 20 |
| Warm-season crops | |||
| Tomatoes | Jan 10 – 24 | Mar 7 – 21 | – |
| Peppers | Jan 3 – 17 | Mar 14 – 28 | – |
| Cucumbers | – | Mar 7 – 28 | – |
| Zucchini | – | Mar 7 – Apr 4 | – |
| Pumpkins | – | Mar 7 – 28 | – |
| Green beans | – | Mar 7 – Oct 2 | – |
| Sweet corn | – | Mar 7 – Apr 4 | – |
| Basil | Jan 31 – Feb 14 | Mar 14 – 21 | – |
Onions: from sets. Green beans: until 10 weeks before the first fall frost. Garlic: harvest next summer.
The year at a glance
Start indoors Plant outside Fall planting
The chance of frost, by date
| 1 year in 10 | Half of years | 9 years in 10 | |
|---|---|---|---|
| Spring frost after | March 7 | January 31 | December 23 |
| Fall frost before | November 20 | December 11 | January 13 |
Frost here means 32°F or colder. Read across: in 1 year in 10, spring frost carries on past the first date, which is why that date is the safe-to-plant date.
Hard freeze (28°F)
A hard freeze kills most garden plants, even hardy ones. The last one in spring usually comes around January 3 (February 1 in a late year), and the first one in fall around December 28.
Towns that use these dates
This is the nearest NOAA station with frost records for 1 town.
San Luis Obispo
Where these dates come from
NOAA weather station SAN LUIS OBISPO AP, CA US (USW00093206), 1991–2020 climate normals. It's the nearest station for 2 zip codes, all within 10 miles:
93401, 93420
Planting dates follow common university extension advice; your local extension service can fine-tune them for your soil and microclimate.