When to plant in Redwood City, CA
USDA Zone 10aEverything below — frost dates, hardiness zone, and what to plant when in Redwood City, California — is derived from the closest NOAA station with complete climate normals.
Redwood City enjoys a long ~329-day frost-free season — you can succession-sow, fit in a second crop, and grow long-season heat-lovers with room to spare. Zone 10a is warm enough that Redwood City can grow subtropical perennials, and the short (or absent) frost period barely limits the annual calendar.
The average last spring frost in Redwood City is now 6 days earlier than in the 1981–2010 normals. See how frost dates are shifting nationwide →
Frost probability
REDWOOD CITY · 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 Redwood City’s own odds, recorded at REDWOOD CITY.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Mar 31 | Feb 25 | Jan 25 | Nov 8 | Nov 25 | Dec 14 |
| 32°F | Feb 16 | Jan 17 | Dec 20 | Nov 24 | Dec 12 | Jan 14 |
| 28°F | Jan 22 | Dec 31 | Dec 14 | Dec 5 | Dec 26 | Jan 15 |
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 Redwood City, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 10 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.
Redwood City planting FAQ
When is the last spring frost in Redwood City, CA?
Plan for the last spring frost in Redwood City around January 17 (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 Redwood City, CA?
In Redwood City, the first 32°F freeze of fall lands around December 12 on average. Time your last harvests and any season-extension cover before it.
What hardiness zone is Redwood City in?
Redwood City is in USDA hardiness zone 10a. In zone 10a, winters are mild — many tender perennials overwinter here.
How long is the growing season in Redwood City?
There are roughly 329 frost-free days in Redwood City (a long growing season), running from the average last frost around January 17 to the first fall frost near December 12.
When should I plant tomatoes in Redwood City?
In Redwood City, start tomato seeds indoors around November 22–December 6, then transplant seedlings outdoors around January 24 once the danger of frost has passed.
Never miss a window in Redwood City
An email when it’s time to start seeds, transplant, and sow — timed to Redwood City’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- North Fair Oaks · 5 km
- San Carlos · 5 km
- Foster City · 6 km
- Menlo Park · 7 km
- Belmont · 7 km
- East Palo Alto · 9 km
- San Mateo · 10 km
- Stanford · 11 km
Frost dates recorded at REDWOOD CITY, 5 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 Redwood City, CA — Frost Dates & Zone 10a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00047339. Retrieved from https://blissgarden.com/california/redwood-city.