When to plant in Newark, CA
USDA Zone 10aEverything below — frost dates, hardiness zone, and what to plant when in Newark, California — is derived from the closest NOAA station with complete climate normals.
With about 360 frost-free days, Newark supports back-to-back plantings; stagger sowings every few weeks to keep beds productive spring through fall. Zone 10a is warm enough that Newark can grow subtropical perennials, and the short (or absent) frost period barely limits the annual calendar.
Frost probability
NEWARK · 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 Newark’s own odds, recorded at NEWARK.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Feb 28 | Jan 19 | Dec 24 | Nov 27 | Dec 15 | Jan 9 |
| 32°F | Jan 22 | Jan 1 | Dec 16 | Dec 9 | Dec 27 | Jan 14 |
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 Newark, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 11 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.
Newark planting FAQ
When is the last spring frost in Newark, CA?
Newark's average last spring frost falls near January 1 — 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 Newark, CA?
The first fall frost in Newark typically arrives around December 27 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.
What hardiness zone is Newark in?
Newark is in USDA hardiness zone 10a. In zone 10a, winters are mild — many tender perennials overwinter here.
How long is the growing season in Newark?
There are roughly 360 frost-free days in Newark (a long growing season), running from the average last frost around January 1 to the first fall frost near December 27.
When should I plant tomatoes in Newark?
In Newark, start tomato seeds indoors around November 6–November 20, then transplant seedlings outdoors around January 8 once the danger of frost has passed.
Never miss a window in Newark
An email when it’s time to start seeds, transplant, and sow — timed to Newark’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Fremont · 8 km
- East Palo Alto · 10 km
- Menlo Park · 11 km
- Union City · 11 km
- Mountain View · 12 km
- Sunnyvale · 13 km
- Milpitas · 15 km
- Stanford · 15 km
Frost dates recorded at NEWARK, 1 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 Newark, CA — Frost Dates & Zone 10a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00046144. Retrieved from https://blissgarden.com/california/newark.