Frost dates for 53809Fennimore, WI
The average last spring frost in Fennimore is April 27 and the average first fall frost is October 11, giving a typical growing season of about 166 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 27
- Average first fall frost
- Oct 11
- Growing season
- 166 days
Safer after May 11 (1-in-10 risk)
Possible by Sep 27 (1-in-10 risk)
Last frost typically in 176 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 23 · May 6 · May 20 | Sep 19 · Oct 2 · Oct 15 | 147 days | 100% |
| Frost / freeze (32°F) | Apr 11 · Apr 27 · May 11 | Sep 27 · Oct 11 · Oct 24 | 166 days | 100% |
| Hard freeze (28°F) | Apr 3 · Apr 16 · May 1 | Oct 6 · Oct 22 · Nov 3 | 189 days | 100% |
Planting calendar for Fennimore
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 27 – Jun 2 |
| Tomatoes | Transplant outdoors | May 13 – Jun 21 |
| Peppers | Start seeds indoors | Mar 27 – Apr 27 |
| Peppers | Transplant outdoors | May 27 – Jun 27 |
| Eggplant | Start seeds indoors | Apr 13 – May 12 |
| Eggplant | Transplant outdoors | May 27 – Jun 27 |
| Cucumbers | Sow outdoors | May 27 – Jul 1 |
| Summer squash | Sow outdoors | May 13 – Jun 27 |
| Winter squash & pumpkins | Sow outdoors | May 27 – Jun 27 |
| Snap beans | Sow outdoors | May 13 – Jul 24 |
| Sweet corn | Sow outdoors | May 13 – Jun 21 |
| Watermelon & cantaloupe | Sow outdoors | May 27 – Jun 27 |
| Okra | Sow outdoors | May 20 – Jun 12 |
| Peas | Sow outdoors (spring) | Mar 27 – May 12 |
| Potatoes | Plant outdoors (spring) | Mar 27 – May 27 |
| Onions | Start seeds indoors (spring) | Feb 13 – Mar 12 |
| Onions | Transplant outdoors (spring) | Apr 13 – May 12 |
| Broccoli | Start seeds indoors (spring) | Mar 9 – Apr 12 |
| Broccoli | Transplant outdoors (spring) | Apr 13 – May 12 |
| Broccoli | Start seeds indoors (fall) | Jun 11 – Jun 21 |
| Broccoli | Transplant outdoors (fall) | Jul 11 – Jul 22 |
| Cabbage | Start seeds indoors (spring) | Feb 27 – Mar 27 |
| Cabbage | Transplant outdoors (spring) | Mar 27 – Apr 27 |
| Cabbage | Start seeds indoors (fall) | Jun 1 – Jul 1 |
| Cabbage | Transplant outdoors (fall) | Jul 1 – Aug 1 |
| Leaf lettuce | Sow outdoors (spring) | Mar 27 – Jun 12 |
| Leaf lettuce | Sow outdoors (fall) | Jul 1 – Aug 17 |
| Spinach | Sow outdoors (spring) | Mar 20 – May 3 |
| Spinach | Sow outdoors (fall) | Jul 18 – Aug 22 |
| Radishes | Sow outdoors (spring) | Mar 27 – May 17 |
| Radishes | Sow outdoors (fall) | Jul 1 – Sep 1 |
| Kale | Sow outdoors (spring) | Apr 13 – May 3 |
| Kale | Sow outdoors (fall) | Jun 24 – Aug 1 |
| Carrots | Sow outdoors (spring) | Apr 27 – Jun 12 |
| Carrots | Sow outdoors (fall) | Jun 1 – Jul 17 |
| Garlic | Plant outdoors (fall) | Oct 1 – Nov 1 |
Where these dates come from
ZIP code 53809 is matched to the NOAA station Lancaster 4 Wsw, WI, 20.9 km away, at 1,040 ft elevation (167 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Lancaster 4 Wsw, WI (used) | 1,040 ft | Apr 27 | Oct 11 |
| Boscobel Ap, WI | 672 ft | May 3 | Oct 7 |
| Steuben 4 Se, WI | 1,015 ft | Apr 22 | Oct 20 |
| Platteville, WI | 990 ft | Apr 30 | Oct 13 |
Frost dates near Fennimore
- Stitzer, WI 53825 · last Apr 27, first Oct 11
- Woodman, WI 53827 · last May 3, first Oct 7
- Lancaster, WI 53813 · last Apr 27, first Oct 11
- Montfort, WI 53569 · last May 3, first Oct 7
- Boscobel, WI 53805 · last May 3, first Oct 7
- Mount Hope, WI 53816 · last Apr 27, first Oct 11
- Livingston, WI 53554 · last Apr 30, first Oct 13
- Bloomington, WI 53804 · last Apr 27, first Oct 11
Frequently asked questions
- When is the last frost in Fennimore, WI?
- For ZIP code 53809, the average last spring frost (32°F) is April 27, based on NOAA 1991-2020 climate normals for the Lancaster 4 Wsw, WI weather station. There is a 1-in-10 chance of a frost after May 11.
- When is the first frost in Fennimore, WI?
- The average first fall frost (32°F) is October 11. There is a 1-in-10 chance of frost by September 27, so tender plants are at risk from that point on.
- How long is the growing season in 53809?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 166 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.