Frost dates for San Luis Obispo Poly, 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 16
typical year
Safe to plant
February 26
frost is over in 9 of 10 years
First fall frost
December 25
typical year
Growing season
349 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 | – | Dec 19 – Jan 2 | – |
| Spinach | – | Dec 5 – 26 | Oct 30 – Nov 13 |
| Lettuce | – | Dec 19 – Jan 9 | Oct 30 – Nov 13 |
| Radishes | – | Dec 19 – Jan 30 | Nov 13 – 27 |
| Onions | – | Dec 19 – Jan 2 | – |
| Potatoes | – | Dec 26 – Jan 9 | – |
| Carrots | – | Dec 26 – Jan 16 | Oct 2 – 16 |
| Beets | – | Dec 19 – Jan 2 | Oct 16 – 30 |
| Kale | Nov 7 – 21 | Dec 19 – Jan 2 | Oct 16 – 30 |
| Broccoli | Nov 7 – 21 | Jan 2 – 16 | Oct 16 – 30 |
| Cabbage | Oct 24 – Nov 7 | Dec 19 – Jan 2 | Oct 16 – 30 |
| Garlic | – | – | Nov 13 – Dec 4 |
| Warm-season crops | |||
| Tomatoes | Jan 1 – 15 | Feb 26 – Mar 12 | – |
| Peppers | Dec 25 – Jan 8 | Mar 5 – 19 | – |
| Cucumbers | – | Feb 26 – Mar 19 | – |
| Zucchini | – | Feb 26 – Mar 26 | – |
| Pumpkins | – | Feb 26 – Mar 19 | – |
| Green beans | – | Feb 26 – Oct 16 | – |
| Sweet corn | – | Feb 26 – Mar 26 | – |
| Basil | Jan 22 – Feb 5 | Mar 5 – 12 | – |
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 | February 26 | January 16 | December 11 |
| Fall frost before | November 25 | December 25 | February 12 |
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 9 (February 22 in a late year), and the first one in fall around January 6.
Where these dates come from
NOAA weather station SAN LUIS OBISPO POLY, CA US (USC00047851), 1991–2020 climate normals. It's the nearest station for 5 zip codes, all within 4 miles:
93405, 93407, 93408, 93409, 93410
Planting dates follow common university extension advice; your local extension service can fine-tune them for your soil and microclimate.