ZIP 61761 Zone 6a
Illinois · USDA zone 6a, average annual extreme minimum -10°F to -5°F.
Nearest qualified station: NORMAL 4NE, IL US (USC00116200), 1.5 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 11 | Earlier date. A last 32°F on or after this day is common. |
| 50% | April 25 | Median. |
| 10% | May 11 | 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 2 | Earlier date. A first 32°F on or before this day is uncommon. |
| 50% | October 16 | Median. |
| 90% | October 29 | 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% | 192 |
| 50% | 172 |
| 90% | 152 |
28°F threshold
| 10% | 50% | 90% | |
|---|---|---|---|
| Last, on or after | May 1 | April 14 | April 1 |
| First, on or before | October 12 | October 27 | November 12 |
| Season at least | 215 days | 195 days | 173 days |
36°F threshold
| 10% | 50% | 90% | |
|---|---|---|---|
| Last, on or after | May 22 | May 4 | April 21 |
| First, on or before | September 23 | October 5 | October 18 |
| Season at least | 170 days | 153 days | 133 days |
Station NORMAL 4NE, IL US (USC00116200). 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 100%. Freeze dates are conditional on that threshold occurring. Elevation 240.8 m. The same probability language applies to the 28°F and 36°F rows when those dates passed the same quality checks.