When to plant in Muscoy, CA
USDA Zone 10aEverything below — frost dates, hardiness zone, and what to plant when in Muscoy, California — is derived from the closest NOAA station with complete climate normals.
Muscoy's nearest full-normals station sits about 18 km out, so treat these as a close estimate — local microclimate can nudge your first and last frost. Zone 10a is warm enough that Muscoy can grow subtropical perennials, and the short (or absent) frost period barely limits the annual calendar.
Frost probability
LAKE ARROWHEAD · 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 Muscoy’s own odds, recorded at LAKE ARROWHEAD.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Jun 10 | May 27 | May 3 | Sep 30 | Oct 18 | Nov 5 |
| 32°F | May 31 | May 5 | Apr 9 | Oct 12 | Nov 2 | Nov 15 |
| 28°F | May 12 | Apr 11 | Mar 14 | Oct 31 | Nov 16 | Nov 30 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Full-year planting calendar
Each bar is the exact window to take a planting action in Muscoy, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 21 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.
Muscoy planting FAQ
When is the last spring frost in Muscoy, CA?
Plan for the last spring frost in Muscoy around May 5 (the date it has a 50% chance of a 32°F freeze). Anything frost-sensitive should go out after it.
When is the first fall frost in Muscoy, CA?
In Muscoy, the first 32°F freeze of fall lands around November 2 on average. Time your last harvests and any season-extension cover before it.
What hardiness zone is Muscoy in?
Muscoy is in USDA hardiness zone 10a. In zone 10a, winters are mild — many tender perennials overwinter here.
How long is the growing season in Muscoy?
There are roughly 181 frost-free days in Muscoy (a moderate growing season), running from the average last frost around May 5 to the first fall frost near November 2.
When should I plant tomatoes in Muscoy?
In Muscoy, start tomato seeds indoors around March 10–March 24, then transplant seedlings outdoors around May 12 once the danger of frost has passed.
Never miss a window in Muscoy
An email when it’s time to start seeds, transplant, and sow — timed to Muscoy’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- San Bernardino · 5 km
- Rialto · 6 km
- Colton · 11 km
- Bloomington · 12 km
- Fontana · 12 km
- Grand Terrace · 14 km
- Loma Linda · 16 km
- Highland · 17 km
Frost dates recorded at LAKE ARROWHEAD, 18 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 Muscoy, CA — Frost Dates & Zone 10a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00044671. Retrieved from https://blissgarden.com/california/muscoy.