ZIP 94928 Zone 9a
California · USDA zone 9a, average annual extreme minimum 20°F to 25°F.
Nearest qualified station: PETALUMA AP, CA US (USC00046826), 7.7 miles from the Census ZCTA internal point for this ZIP.
Outside the median season Growing seasonTicks: 10%, 50%, and 90%
Last 32°F in spring
NCEI’s probability is the chance the last spring minimum of 32°F or lower occurs on or after the date.
| Probability | Date | How to read it |
|---|---|---|
| 90% | January 24 | Earlier date. A last 32°F on or after this day is common. |
| 50% | February 28 | Median. |
| 10% | April 6 | Later date. A last 32°F on or after this day is uncommon. |
First 32°F in fall
NCEI’s probability is the chance the first autumn minimum of 32°F or lower occurs on or before the date.
| Probability | Date | How to read it |
|---|---|---|
| 10% | November 9 | Earlier date. A first 32°F on or before this day is uncommon. |
| 50% | November 25 | Median. |
| 90% | December 16 | Later date. A first 32°F on or before this day is common. |
32°F growing-season length
Days between the last spring 32°F and the first autumn 32°F. The figure is a length the season meets or exceeds at that probability, from NCEI, not a subtraction done on this site.
| Probability the season is at least this long | Days |
|---|---|
| 10% | 313 |
| 50% | 271 |
| 90% | 230 |
28°F threshold
| 10% | 50% | 90% | |
|---|---|---|---|
| Last, on or after | February 24 | January 17 | December 17 |
| First, on or before | November 20 | December 9 | January 12 |
| Season at least | 365 days | 331 days | 289 days |
36°F threshold
| 10% | 50% | 90% | |
|---|---|---|---|
| Last, on or after | April 27 | April 6 | March 7 |
| First, on or before | October 27 | November 10 | November 28 |
| Season at least | 249 days | 218 days | 193 days |
Station PETALUMA AP, CA US (USC00046826). Completeness flag S, 26 years used for the 32°F dates. NCEI’s annual probability of at least one day at or below 32°F is 99.5%. Freeze dates are conditional on that threshold occurring. Elevation 6.1 m. The same probability language applies to the 28°F and 36°F rows when those dates passed the same quality checks.