Frost dates for 91770 — Rosemead, CA
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 Rosemead compares
- In a typical year, frost nights in Rosemead fall between January 2 and January 4. In 1 year in 10 the first frost comes as early as December 18, or the last frost as late as January 28.
- Rosemead shares its weather station with Monterey Park, CA, 4 km away, so the two have the same frost dates.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | December 19 |
| 50% (median) | January 4 |
| 10% (safe for tender plants) | January 28 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | December 18 |
| 50% (median) | January 2 |
| 90% (late) | January 26 |
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
Rosemead, 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 San Gabriel Fire Dept, CA weather station, 2 km away (elevation 364 ft (111 m)).
ZIP codes in Rosemead: 91770 91771 91772
Frost dates near Rosemead
- Monterey Park Jan 4 · Jan 2
- San Gabriel Jan 4 · Jan 2
- South El Monte Jan 4 · Jan 2
- Temple City Jan 4 · Jan 2
- Alhambra Jan 4 · Jan 2
- El Monte Jan 4 · Jan 2
- Montebello Jan 4 · Jan 2
- San Marino Jan 4 · Jan 2
Frequently asked questions
When is the last frost in Rosemead, CA?
The median last spring frost in Rosemead, CA is January 4. There is still about a 10% chance of frost after January 28, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Rosemead, CA?
The median first fall frost is January 2, with about a 10% chance of frost before December 18.
How long is the growing season in Rosemead, CA?
About 363 days between the median last spring frost and first fall frost.
What planting zone is Rosemead, CA?
Rosemead, CA is in USDA hardiness zone 10b.