When to plant in National City, CA
USDA Zone 10bNational City, California frost dates, USDA zone, and a full-year planting calendar, drawn from the nearest NOAA station and tuned to the local season.
A generous ~359-day season lets National City gardeners direct-sow more and still ripen long-maturity crops like melons and winter squash. Heads up: the nearest complete-normals station is about 15 km from National City, so your yard's frost dates can differ — a low spot or a paved city center can shift them by a week. Zone 10b is warm enough that National City can grow subtropical perennials, and the short (or absent) frost period barely limits the annual calendar.
Frost probability
SAN DIEGO BROWN FLD · 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 National City’s own odds, recorded at SAN DIEGO BROWN FLD.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Mar 7 | Feb 2 | Dec 29 | Dec 1 | Dec 20 | Jan 25 |
| 32°F | Feb 5 | Jan 6 | Dec 13 | Dec 11 | Dec 31 | Jan 30 |
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 National City, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 36 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.
National City planting FAQ
When is the last spring frost in National City, CA?
National City's average last spring frost falls near January 6 — 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 National City, CA?
The first fall frost in National City typically arrives around December 31 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.
What hardiness zone is National City in?
National City is in USDA hardiness zone 10b. In zone 10b, winters are mild — many tender perennials overwinter here.
How long is the growing season in National City?
There are roughly 359 frost-free days in National City (a long growing season), running from the average last frost around January 6 to the first fall frost near December 31.
When should I plant tomatoes in National City?
In National City, start tomato seeds indoors around November 11–November 25, then transplant seedlings outdoors around January 13 once the danger of frost has passed.
Never miss a window in National City
An email when it’s time to start seeds, transplant, and sow — timed to National City’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Coronado · 5 km
- Bonita · 9 km
- Chula Vista · 9 km
- Lemon Grove · 10 km
- La Presa · 10 km
- Imperial Beach · 11 km
- Spring Valley · 14 km
- La Mesa · 14 km
Frost dates recorded at SAN DIEGO BROWN FLD, 15 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 National City, CA — Frost Dates & Zone 10b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00003178. Retrieved from https://blissgarden.com/california/national-city.