Frost dates for Hetch Hetchy, 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
April 16
typical year
Safe to plant
May 12
frost is over in 9 of 10 years
First fall frost
November 12
typical year
Growing season
208 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 | – | Mar 19 – Apr 2 | – |
| Spinach | – | Mar 5 – 26 | Sep 17 – Oct 1 |
| Lettuce | – | Mar 19 – Apr 9 | Sep 17 – Oct 1 |
| Radishes | – | Mar 19 – Apr 30 | Oct 1 – 15 |
| Onions | – | Mar 19 – Apr 2 | – |
| Potatoes | – | Mar 26 – Apr 9 | – |
| Carrots | – | Mar 26 – Apr 16 | Aug 20 – Sep 3 |
| Beets | – | Mar 19 – Apr 2 | Sep 3 – 17 |
| Kale | Feb 5 – 19 | Mar 19 – Apr 2 | Sep 3 – 17 |
| Broccoli | Feb 5 – 19 | Apr 2 – 16 | Sep 3 – 17 |
| Cabbage | Jan 22 – Feb 5 | Mar 19 – Apr 2 | Sep 3 – 17 |
| Garlic | – | – | Oct 1 – 22 |
| Warm-season crops | |||
| Tomatoes | Mar 17 – 31 | May 12 – 26 | – |
| Peppers | Mar 10 – 24 | May 19 – Jun 2 | – |
| Cucumbers | – | May 12 – Jun 2 | – |
| Zucchini | – | May 12 – Jun 9 | – |
| Pumpkins | – | May 12 – Jun 2 | – |
| Green beans | – | May 12 – Sep 3 | – |
| Sweet corn | – | May 12 – Jun 9 | – |
| Basil | Apr 7 – 21 | May 19 – 26 | – |
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 | May 12 | April 16 | March 24 |
| Fall frost before | October 24 | November 12 | December 1 |
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 March 25 (April 17 in a late year), and the first one in fall around November 28.
Where these dates come from
NOAA weather station HETCH HETCHY, CA US (USC00043939), 1991–2020 climate normals. It's the nearest station for 2 zip codes, all within 18 miles:
95321, 95364
Planting dates follow common university extension advice; your local extension service can fine-tune them for your soil and microclimate.