ZIP 23518 Zone 8b
Virginia · USDA zone 8b, average annual extreme minimum 15°F to 20°F.
Nearest qualified station: NORFOLK INTL AP, VA US (USW00013737), 1.6 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% | February 27 | Earlier date. A last 32°F on or after this day is common. |
| 50% | March 17 | Median. |
| 10% | March 31 | 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 8 | Earlier date. A first 32°F on or before this day is uncommon. |
| 50% | November 23 | Median. |
| 90% | December 10 | 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% | 275 |
| 50% | 252 |
| 90% | 231 |
28°F threshold
| 10% | 50% | 90% | |
|---|---|---|---|
| Last, on or after | March 20 | March 4 | February 10 |
| First, on or before | November 19 | December 8 | January 2 |
| Season at least | 309 days | 281 days | 254 days |
36°F threshold
| 10% | 50% | 90% | |
|---|---|---|---|
| Last, on or after | April 12 | March 30 | March 14 |
| First, on or before | October 31 | November 11 | November 26 |
| Season at least | 248 days | 227 days | 207 days |
Station NORFOLK INTL AP, VA US (USW00013737). Completeness flag S, 30 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 9.1 m. The same probability language applies to the 28°F and 36°F rows when those dates passed the same quality checks.