Frost dates / Minnesota / Cottage Grove
Frost dates in Cottage Grove, MN
The station on this page is HASTINGS DAM 2, MN US (USC00213567), 4.3 miles from the city point. Population in the Census 2024 estimate is 42,760.
Zone 5aUSDA average annual extreme minimum -20°F to -15°F, from ZIP 55016 (1 miles from the city point used on this page).
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 8 | Earlier date. A last 32°F on or after this day is common. |
| 50% | April 23 | Median. |
| 10% | May 7 | 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 5 | Earlier date. A first 32°F on or before this day is uncommon. |
| 50% | October 19 | 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% | 197 |
| 50% | 177 |
| 90% | 157 |
28°F threshold
| 10% | 50% | 90% | |
|---|---|---|---|
| Last, on or after | April 30 | April 11 | April 1 |
| First, on or before | October 14 | October 30 | November 12 |
| Season at least | 216 days | 198 days | 178 days |
36°F threshold
| 10% | 50% | 90% | |
|---|---|---|---|
| Last, on or after | May 19 | May 4 | April 19 |
| First, on or before | September 26 | October 8 | October 22 |
| Season at least | 176 days | 156 days | 138 days |
Station HASTINGS DAM 2, MN US (USC00213567). 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 207.3 m. The same probability language applies to the 28°F and 36°F rows when those dates passed the same quality checks.
Check a crop against this station
Cottage Grove, MN
Zone 5aAverage annual extreme minimum -20°F to -15°F
Outside the median season Growing seasonTicks: 10%, 50%, and 90%
Minnesota. Nearest qualified station: HASTINGS DAM 2, MN US (USC00213567), 4.3 miles. Median last 32°F April 23. Median first 32°F October 19. The 50% growing-season length is 177 days.
32°F probabilities at this station
| 10% | 50% | 90% | |
|---|---|---|---|
| Last 32°F on or after | May 7 | April 23 | April 8 |
| First 32°F on or before | October 5 | October 19 | November 1 |
Column order matches the NCEI file: for the last freeze, 10% is the later date and 90% is the earlier date. How to read the probabilities.

Planting calendar
Frost dates for Minnesota are above. Planting windows appear for states with a cited extension guide. The fall and seed tools use the numbers you enter and the station dates.
Date checks use your device’s calendar and appear after the page loads.