When to plant in Atwater, CA
USDA Zone 9aHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Atwater, California — all computed from Atwater's nearest NOAA weather station.
With about 266 frost-free days, Atwater supports back-to-back plantings; stagger sowings every few weeks to keep beds productive spring through fall. In zone 9a, frost is a minor factor for Atwater — most perennials thrive, and annual vegetables can go out early and stay late.
Frost probability
MERCED · 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 Atwater’s own odds, recorded at MERCED.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 1 | Apr 7 | Mar 6 | Oct 21 | Nov 8 | Nov 24 |
| 32°F | Apr 10 | Mar 3 | Feb 2 | Nov 5 | Nov 24 | Dec 14 |
| 28°F | Mar 11 | Feb 2 | Dec 28 | Nov 22 | Dec 11 | 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 Atwater, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 27 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.
Atwater planting FAQ
When is the last spring frost in Atwater, CA?
Atwater's average last spring frost falls near March 3 — 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 Atwater, CA?
The first fall frost in Atwater typically arrives around November 24 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.
What hardiness zone is Atwater in?
Atwater is in USDA hardiness zone 9a. In zone 9a, winters are mild — many tender perennials overwinter here.
How long is the growing season in Atwater?
Atwater has about 266 frost-free days — a long growing season — between the average last spring frost (March 3) and first fall frost (November 24).
When should I plant tomatoes in Atwater?
For Atwater, sow tomatoes indoors about January 6–January 20 and move the seedlings out around March 10, after the last spring frost.
Never miss a window in Atwater
An email when it’s time to start seeds, transplant, and sow — timed to Atwater’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Winton · 4 km
- Livingston · 12 km
- Merced · 12 km
- Delhi · 18 km
- Turlock · 29 km
- Newman · 38 km
- Los Banos · 39 km
- Chowchilla · 41 km
Frost dates recorded at MERCED, 10 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 Atwater, CA — Frost Dates & Zone 9a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00045532. Retrieved from https://blissgarden.com/california/atwater.