Frost dates for 53527Cottage Grove, WI
The average last spring frost in Cottage Grove is May 1 and the average first fall frost is October 10, giving a typical growing season of about 160 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 1
- Average first fall frost
- Oct 10
- Growing season
- 160 days
Safer after May 16 (1-in-10 risk)
Possible by Sep 26 (1-in-10 risk)
Last frost typically in 181 days
Frost risk by date
NOAA reports frost dates as probabilities. The middle date is the average (a 50% chance). For spring, the 10% date is a safer planting date: frost after it happens in about 1 year in 10. Light frost (36°F) can damage tender plants; a hard freeze (28°F) kills most annuals.
| Temperature | Last spring: 90% / 50% / 10% chance | First fall: 10% / 50% / 90% chance | Growing season (50%) | Years with at least one |
|---|---|---|---|---|
| Light frost (36°F) | Apr 29 · May 13 · May 29 | Sep 17 · Sep 29 · Oct 12 | 139 days | 100% |
| Frost / freeze (32°F) | Apr 16 · May 1 · May 16 | Sep 26 · Oct 10 · Oct 24 | 160 days | 100% |
| Hard freeze (28°F) | Apr 5 · Apr 20 · May 5 | Oct 6 · Oct 22 · Nov 4 | 182 days | 100% |
Planting calendar for Cottage Grove
Planting windows from the University of Maryland Extension calendar, shifted to your average frost dates. Use them as a starting point and adjust for seed packet instructions and local conditions.
| Crop | Task | Window |
|---|---|---|
| Tomatoes | Start seeds indoors | Mar 31 – Jun 6 |
| Tomatoes | Transplant outdoors | May 17 – Jun 20 |
| Peppers | Start seeds indoors | Mar 31 – May 1 |
| Peppers | Transplant outdoors | May 31 – Jul 1 |
| Eggplant | Start seeds indoors | Apr 17 – May 16 |
| Eggplant | Transplant outdoors | May 31 – Jul 1 |
| Cucumbers | Sow outdoors | May 31 – Jun 30 |
| Summer squash | Sow outdoors | May 17 – Jul 1 |
| Winter squash & pumpkins | Sow outdoors | May 31 – Jul 1 |
| Snap beans | Sow outdoors | May 17 – Jul 23 |
| Sweet corn | Sow outdoors | May 17 – Jun 20 |
| Watermelon & cantaloupe | Sow outdoors | May 31 – Jul 1 |
| Okra | Sow outdoors | May 24 – Jun 16 |
| Peas | Sow outdoors (spring) | Mar 31 – May 16 |
| Potatoes | Plant outdoors (spring) | Mar 31 – May 31 |
| Onions | Start seeds indoors (spring) | Feb 17 – Mar 16 |
| Onions | Transplant outdoors (spring) | Apr 17 – May 16 |
| Broccoli | Start seeds indoors (spring) | Mar 13 – Apr 16 |
| Broccoli | Transplant outdoors (spring) | Apr 17 – May 16 |
| Broccoli | Start seeds indoors (fall) | Jun 10 – Jun 20 |
| Broccoli | Transplant outdoors (fall) | Jul 10 – Jul 21 |
| Cabbage | Start seeds indoors (spring) | Mar 3 – Mar 31 |
| Cabbage | Transplant outdoors (spring) | Mar 31 – May 1 |
| Cabbage | Start seeds indoors (fall) | May 31 – Jun 30 |
| Cabbage | Transplant outdoors (fall) | Jun 30 – Jul 31 |
| Leaf lettuce | Sow outdoors (spring) | Mar 31 – Jun 16 |
| Leaf lettuce | Sow outdoors (fall) | Jun 30 – Aug 16 |
| Spinach | Sow outdoors (spring) | Mar 24 – May 7 |
| Spinach | Sow outdoors (fall) | Jul 17 – Aug 21 |
| Radishes | Sow outdoors (spring) | Mar 31 – May 21 |
| Radishes | Sow outdoors (fall) | Jun 30 – Aug 31 |
| Kale | Sow outdoors (spring) | Apr 17 – May 7 |
| Kale | Sow outdoors (fall) | Jun 23 – Jul 31 |
| Carrots | Sow outdoors (spring) | May 1 – Jun 16 |
| Carrots | Sow outdoors (fall) | May 31 – Jul 16 |
| Garlic | Plant outdoors (fall) | Sep 30 – Oct 31 |
Where these dates come from
ZIP code 53527 is matched to the NOAA station Madison Dane Rgnl Ap, WI, 13.6 km away, at 866 ft elevation (46 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Madison Dane Rgnl Ap, WI (used) | 866 ft | May 1 | Oct 10 |
| Stoughton, WI | 840 ft | Apr 30 | Oct 11 |
| Uw Arboretum - Madison, WI | 870 ft | May 1 | Oct 9 |
| Waterloo Wwtp, WI | 800 ft | Apr 30 | Oct 9 |
Frost dates near Cottage Grove
- Madison, WI 53718 · last May 1, first Oct 10
- Deerfield, WI 53531 · last Apr 29, first Oct 14
- Mc Farland, WI 53558 · last May 1, first Oct 9
- Sun Prairie, WI 53590 · last May 1, first Oct 10
- Marshall, WI 53559 · last Apr 29, first Oct 14
- Stoughton, WI 53589 · last Apr 30, first Oct 11
- Cambridge, WI 53523 · last Apr 29, first Oct 14
- Windsor, WI 53598 · last May 1, first Oct 10
Frequently asked questions
- When is the last frost in Cottage Grove, WI?
- For ZIP code 53527, the average last spring frost (32°F) is May 1, based on NOAA 1991-2020 climate normals for the Madison Dane Rgnl Ap, WI weather station. There is a 1-in-10 chance of a frost after May 16.
- When is the first frost in Cottage Grove, WI?
- The average first fall frost (32°F) is October 10. There is a 1-in-10 chance of frost by September 26, so tender plants are at risk from that point on.
- How long is the growing season in 53527?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 160 days long.
- Are these frost dates a forecast?
- No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.