Sylmar, 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 Sylmar compares
- In a typical year, frost nights in Sylmar fall between January 1 and January 2. In 1 year in 10 the first frost comes as early as December 9, or the last frost as late as January 27.
- Compared with Santa Clarita, CA, 15 km away, the last frost here is 6 days earlier than there.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | December 10 |
| 50% (median) | January 2 |
| 10% (safe for tender plants) | January 27 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | December 9 |
| 50% (median) | January 1 |
| 90% (late) | January 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
Sylmar, 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 Northridge Cal State, CA weather station, 10 km away (elevation 906 ft (276 m)).
ZIP codes in Sylmar: 91342 91392
Frost dates near Sylmar
- San Fernando Jan 2 · Jan 1
- Pacoima Dec 31 · Dec 30
- Mission Hills Jan 2 · Jan 1
- Granada Hills Jan 2 · Jan 1
- North Hills Dec 31 · Dec 30
- Panorama City Dec 31 · Dec 30
- Newhall Jan 8 · Jan 1
- Sun Valley Dec 31 · Dec 28
- Sunland Dec 31 · Dec 28
- Northridge Jan 2 · Jan 1
Frequently asked questions
When is the last frost in Sylmar, CA?
The median last spring frost in Sylmar, CA is January 2. There is still about a 10% chance of frost after January 27, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Sylmar, CA?
The median first fall frost is January 1, with about a 10% chance of frost before December 9.
How long is the growing season in Sylmar, CA?
About 364 days between the median last spring frost and first fall frost.
What planting zone is Sylmar, CA?
Sylmar, CA is in USDA hardiness zone 10a.