ZIP 51501 Zone 5b
Iowa · USDA zone 5b, average annual extreme minimum -15°F to -10°F.
Nearest qualified station: OMAHA EPPLEY AIRFIELD, NE US (USW00014942), 5.8 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% | April 5 | Earlier date. A last 32°F on or after this day is common. |
| 50% | April 18 | Median. |
| 10% | April 30 | 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% | October 6 | Earlier date. A first 32°F on or before this day is uncommon. |
| 50% | October 21 | Median. |
| 90% | November 1 | 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% | 204 |
| 50% | 185 |
| 90% | 163 |
28°F threshold
| 10% | 50% | 90% | |
|---|---|---|---|
| Last, on or after | April 21 | April 8 | March 24 |
| First, on or before | October 17 | October 30 | November 11 |
| Season at least | 223 days | 204 days | 185 days |
36°F threshold
| 10% | 50% | 90% | |
|---|---|---|---|
| Last, on or after | May 11 | April 28 | April 14 |
| First, on or before | September 27 | October 10 | October 23 |
| Season at least | 184 days | 165 days | 147 days |
Station OMAHA EPPLEY AIRFIELD, NE US (USW00014942). 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 299.3 m. The same probability language applies to the 28°F and 36°F rows when those dates passed the same quality checks.