Piru, CA frost dates
Frost is light and occasional here — typically a few cold nights around midwinter (about 1 a year). Cover tender plants when frost is forecast.
How Piru compares
- In a typical year, frost nights in Piru fall between January 1 and January 8. In 1 year in 10 the first frost comes as early as November 30, or the last frost as late as March 10.
- Compared with Simi Valley, CA, 18 km away, the last frost here is 16 days earlier than there.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | December 8 |
| 50% (median) | January 8 |
| 10% (safe for tender plants) | March 10 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | November 30 |
| 50% (median) | January 1 |
| 90% (late) | February 25 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Gardening where frost is rare
Piru, CA only freezes on a few winter nights, so the usual "plant after the last frost" rule doesn't apply. Heat and rainfall decide the seasons instead:
- Cool-season crops (lettuce, broccoli, peas, carrots) grow best from fall through late winter.
- Warm-season crops (tomatoes, peppers, beans, squash) do best planted in late winter to spring, and again in late summer for a fall crop — midsummer heat can stop tomatoes setting fruit.
- Heat lovers (okra, sweet potatoes, melons) can be planted through spring and early summer.
About these dates
Based on 1991–2020 NOAA climate normals for the Newhall 5nw, CA weather station, 18 km away (elevation 1,765 ft (538 m)).
Frost dates near Piru
- Fillmore Dec 31 · Dec 28
- Castaic Jan 8 · Jan 1
- Stevenson Ranch Jan 8 · Jan 1
- Simi Valley Jan 24 · Dec 15
- Moorpark Dec 31 · Dec 28
- Valencia Jan 8 · Jan 1
- Brandeis Jan 24 · Dec 15
- Santa Clarita Jan 8 · Jan 1
- Newhall Jan 8 · Jan 1
- Chatsworth Jan 2 · Jan 1
Frequently asked questions
When is the last frost in Piru, CA?
The median last spring frost in Piru, CA is January 8. There is still about a 10% chance of frost after March 10, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Piru, CA?
The median first fall frost is January 1, with about a 10% chance of frost before November 30.
How long is the growing season in Piru, CA?
About 358 days between the median last spring frost and first fall frost.
What planting zone is Piru, CA?
Piru, CA is in USDA hardiness zone 8b.