ZIP 23664 Zone 8b
Virginia · USDA zone 8b, average annual extreme minimum 15°F to 20°F.
Nearest qualified station: LANGLEY AFB, VA US (USW00013702), 3.1 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% | March 9 | Earlier date. A last 32°F on or after this day is common. |
| 50% | March 24 | 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 3 | Earlier date. A first 32°F on or before this day is uncommon. |
| 50% | November 15 | Median. |
| 90% | December 2 | 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% | 261 |
| 50% | 238 |
| 90% | 217 |
28°F threshold
| 10% | 50% | 90% | |
|---|---|---|---|
| Last, on or after | March 28 | March 10 | February 22 |
| First, on or before | November 10 | November 28 | December 20 |
| Season at least | 292 days | 266 days | 240 days |
36°F threshold
| 10% | 50% | 90% | |
|---|---|---|---|
| Last, on or after | April 18 | April 4 | March 22 |
| First, on or before | October 25 | November 5 | November 18 |
| Season at least | 234 days | 216 days | 198 days |
Station LANGLEY AFB, VA US (USW00013702). Completeness flag R, 13 years used for the 32°F dates. NCEI’s annual probability of at least one day at or below 32°F is 100%. Freeze dates are conditional on that threshold occurring. Elevation 3 m. The same probability language applies to the 28°F and 36°F rows when those dates passed the same quality checks.