Last frost date in Patterson, CA
The average last frost in Patterson is January 31. By February 25 the chance of another 32°F night drops to 1 in 10. The first fall frost usually arrives about December 5, which leaves 312 frost-free days. An early freeze before November 20 happens one year in ten.
- Safe after (10% risk)
- Feb 25
- Average first frost
- Dec 5
- Frost-free season
- 312 days
- Hard freeze (28°F) ends
- Jan 8
No frost in the next 6 nights
National Weather Service forecast, updated Oct 22, 12:57 UTC
- ThuOct 2254°
- FriOct 2350°
- SatOct 2450°
- SunOct 2552°
- MonOct 2652°
- TueOct 2751°
Planting calendar for Patterson
Windows count forward or back from the average frost dates above. Click a crop for dates across California.
Frost probabilities
| Threshold | Spring, 90% chance later | Spring, 50% | Spring, 10% | Fall, 10% chance earlier | Fall, 50% | Fall, 90% |
|---|---|---|---|---|---|---|
| Light frost, 32°F | Dec 31 | Jan 31 | Feb 25 | Nov 20 | Dec 5 | Jan 6 |
| Hard freeze, 28°F | Dec 16 | Jan 8 | Feb 6 | Dec 1 | Dec 21 | Jan 20 |
Read the spring 10% column as the date after which only one year in ten still gets frost. That is the safer date for tomatoes, peppers and basil.
Where these numbers come from
NOAA station Modesto City County Airport (USW00023258) sits 15.1 miles from the center of Patterson at 73 feet. Its averages cover 1991 to 2020. Low spots, valleys and open fields can keep getting frost a week or two after the station stops; city centers and lakeshores usually get less of it.
Questions
When is the last frost in Patterson, CA?
The average last frost date in Patterson is January 31, based on NOAA 1991–2020 climate normals. There is a 10% chance of frost after February 25.
When is the first frost in Patterson?
The first frost in fall usually comes around December 5. One year in ten it arrives before November 20.
How long is the growing season in Patterson?
About 312 days between the average last and first frost.
When should I plant tomatoes in Patterson?
Plant tomato seedlings outside from February 15 to March 1. Start seeds indoors six to eight weeks earlier.