When to plant in Lathrop, CA
USDA Zone 9bHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Lathrop, California — all computed from Lathrop's nearest NOAA weather station.
A generous ~298-day season lets Lathrop gardeners direct-sow more and still ripen long-maturity crops like melons and winter squash. Zone 9b is warm enough that Lathrop can grow subtropical perennials, and the short (or absent) frost period barely limits the annual calendar.
The average last spring frost in Lathrop is now 13 days earlier than in the 1981–2010 normals. See how frost dates are shifting nationwide →
Frost probability
STOCKTON METRO 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 Lathrop’s own odds, recorded at STOCKTON METRO AP.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Apr 7 | Mar 10 | Feb 11 | Nov 4 | Nov 18 | Dec 2 |
| 32°F | Feb 28 | Feb 6 | Dec 31 | Nov 15 | Dec 1 | Dec 26 |
| 28°F | Feb 5 | Jan 10 | Dec 14 | Nov 29 | Dec 16 | Jan 14 |
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 Lathrop, 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.
Lathrop planting FAQ
When is the last spring frost in Lathrop, CA?
Lathrop's average last spring frost falls near February 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 Lathrop, CA?
Expect Lathrop's first fall frost near December 1 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.
What hardiness zone is Lathrop in?
Lathrop is in USDA hardiness zone 9b. In zone 9b, winters are mild — many tender perennials overwinter here.
How long is the growing season in Lathrop?
There are roughly 298 frost-free days in Lathrop (a long growing season), running from the average last frost around February 6 to the first fall frost near December 1.
When should I plant tomatoes in Lathrop?
In Lathrop, start tomato seeds indoors around December 12–December 26, then transplant seedlings outdoors around February 13 once the danger of frost has passed.
Never miss a window in Lathrop
An email when it’s time to start seeds, transplant, and sow — timed to Lathrop’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Manteca · 8 km
- Tracy · 15 km
- Country Club · 18 km
- Ripon · 18 km
- Stockton · 19 km
- Garden Acres · 19 km
- Mountain House · 20 km
- Salida · 23 km
Frost dates recorded at STOCKTON METRO AP, 12 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 Lathrop, CA — Frost Dates & Zone 9b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00023237. Retrieved from https://blissgarden.com/california/lathrop.