Atwater, CA planting zone & frost dates
Atwater is in USDA hardiness zone 9a. The last spring frost usually comes around March 3 and the first fall frost around November 24, for a growing season of about 263 days.
Planting calendar for Atwater
Dates are counted from the average last spring frost (March 3) using the typical timing recommended by U.S. extension services. Warm-season crops go out only after the danger of frost has passed and the soil has warmed.
| Crop | When |
|---|---|
| Tomatoes | Start seeds indoors: Jan 6 – Jan 20 Transplant outdoors: Mar 10 – Mar 17 |
| Peppers | Start seeds indoors: Dec 23 – Jan 6 Transplant outdoors: Mar 17 – Mar 24 |
| Eggplant | Start seeds indoors: Dec 23 – Jan 6 Transplant outdoors: Mar 17 – Mar 24 |
| Broccoli | Start seeds indoors: Dec 23 – Jan 6 Transplant outdoors: Feb 3 – Feb 17 |
| Cabbage | Start seeds indoors: Dec 23 – Jan 6 Transplant outdoors: Feb 3 – Feb 17 |
| Onions (sets) | Plant outdoors: Feb 3 – Feb 17 |
| Peas | Sow outdoors: Jan 20 – Feb 3 |
| Spinach | Sow outdoors: Jan 20 – Feb 3 |
| Lettuce | Sow outdoors: Feb 3 – Feb 17 |
| Carrots | Sow outdoors: Feb 3 – Feb 17 |
| Potatoes | Plant outdoors: Feb 3 – Feb 17 |
| Beans | Sow outdoors: Mar 10 – Mar 17 |
| Sweet corn | Sow outdoors: Mar 10 – Mar 17 |
| Cucumbers | Sow outdoors: Mar 10 – Mar 17 |
| Squash & zucchini | Sow outdoors: Mar 10 – Mar 17 |
| Basil | Start seeds indoors: Jan 20 – Feb 3 Transplant outdoors: Mar 10 – Mar 17 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Sep 29 (8 weeks before the average first fall frost on Nov 24).
Useful for zone 9a gardens
- Seed starting kit with dome — to start seeds indoors before the last frost
- LED grow light for seedlings — stops leggy seedlings
- Frost cloth / plant covers — for late spring and early fall frosts
- Soil thermometer — warm-season crops need soil above 60°F
- Shade cloth — for hot summers
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Frost risk in detail
| 90% chance | 50% chance | 10% chance | |
|---|---|---|---|
| Last 32°F frost in spring is after | Feb 2 | Mar 3 | Apr 10 |
| First 32°F frost in fall is before | Dec 14 | Nov 24 | Nov 5 |
How to read it: in spring there is a 10% chance of a frost after April 10, so that is a safe date for tender plants. In fall there is a 10% chance of frost before November 5. A hard freeze (28°F) usually ends around February 2.
Hardiness zone by ZIP code in Atwater
- 95301 zone 9a
Nearby cities
- Winton zone 9b, last frost Mar 3
- Livingston zone 9a, last frost Jan 6
- Merced zone 9a, last frost Mar 3
- Delhi zone 9b, last frost Jan 6
- Turlock zone 9b, last frost Jan 6
- Los Banos zone 9a, last frost Jan 26
- Newman zone 9b, last frost Feb 26
- Chowchilla zone 9a, last frost Feb 12
Questions
What growing zone is Atwater, CA?
Atwater is in USDA Plant Hardiness Zone 9a (average extreme winter low 20°F to 25°F), according to the USDA 2023 map.
When is the last frost in Atwater?
The average last spring frost (32°F) in Atwater is March 3. There is still a 10% chance of frost until April 10.
When can I plant tomatoes in Atwater?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Mar 10 – Mar 17. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Merced, CA (USC00045532), 10.5 km (6.5 mi) from the city center, elevation 47 m, based on 22 years of records. Hardiness zone: USDA Plant Hardiness Zone Map 2023 for the ZIP code nearest to the city center. Microclimates (valleys, hills, cities, coasts) can be warmer or colder: check the local forecast before planting. How we calculate the data.