When to plant in Westmont, CA
USDA Zone 10bEverything below — frost dates, hardiness zone, and what to plant when in Westmont, California — is derived from the closest NOAA station with complete climate normals.
A ~-4-day frost-free window makes Westmont a short-season garden: choose early varieties and start long-season crops indoors well ahead of the last frost. These dates come from a station roughly 16 km away, the closest with full normals; terrain around Westmont (elevation, water, pavement) can move your real frost dates a few days either way. In zone 10b, frost is a minor factor for Westmont — most perennials thrive, and annual vegetables can go out early and stay late.
Frost probability
TORRANCE AP · 1991–2020The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Westmont’s own odds, recorded at TORRANCE AP.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Mar 5 | Jan 17 | Dec 12 | Dec 1 | Dec 31 | Feb 20 |
| 32°F | Feb 24 | Jan 9 | Dec 4 | Dec 3 | Jan 5 | Feb 22 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Nothing new to sow or transplant outdoors in the next few weeks — a seasonal lull. Check the full-year calendar below for the next window.
Full-year planting calendar
Each bar is the exact window to take a planting action in Westmont, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 27 km · complete 32°F normalsWhen stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.
Westmont planting FAQ
When is the last spring frost in Westmont, CA?
Westmont's average last spring frost falls near January 9 — the 50% mark at 32°F in the 1991–2020 normals. Hold tender transplants until the risk has passed, then plant out.
When is the first fall frost in Westmont, CA?
Expect Westmont's first fall frost near January 5 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.
What hardiness zone is Westmont in?
Westmont is in USDA hardiness zone 10b. In zone 10b, winters are mild — many tender perennials overwinter here.
How long is the growing season in Westmont?
Westmont has about -4 frost-free days — a short growing season — between the average last spring frost (January 9) and first fall frost (January 5).
When should I plant tomatoes in Westmont?
For Westmont, sow tomatoes indoors about November 14–November 28 and move the seedlings out around January 16, after the last spring frost.
Never miss a window in Westmont
An email when it’s time to start seeds, transplant, and sow — timed to Westmont’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Inglewood · 4 km
- West Rancho Dominguez · 5 km
- Hawthorne · 5 km
- Lennox · 5 km
- Gardena · 5 km
- Florence-Graham · 6 km
- Willowbrook · 6 km
- Del Aire · 7 km
Frost dates recorded at TORRANCE AP, 16 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.
BlissGarden. "When to Plant in Westmont, CA — Frost Dates & Zone 10b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00003122. Retrieved from https://blissgarden.com/california/westmont.