Rock Falls, WI frost dates
How Rock Falls compares
- In 8 years out of 10, the last spring frost in Rock Falls falls between April 9 and May 7, a 28-day window. The first fall frost falls between September 26 and October 28.
- The median last frost is 11 days earlier than the Wisconsin median of May 5.
- Its 173-day growing season is longer than 89% of the 749 Wisconsin places with a regular frost season (state median 155 days).
- The last frost is 14 days earlier than the zone 4b median of May 8. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 4b chart.
- The weather station records an average of 149 nights a year at or below 32°F.
- Rock Falls shares its weather station with Eau Claire, WI, 18 km away, so the two have the same frost dates.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 9 |
| 50% (median) | April 24 |
| 10% (safe for tender plants) | May 7 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 26 |
| 50% (median) | October 14 |
| 90% (late) | October 28 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Planting calendar for Rock Falls, WI
Rock Falls, WI frost dates — last frost Apr 24, first frost Oct 14, zone 4b. whenisthelastfrost.com
When to plant vegetables in Rock Falls, WI
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 30 – Feb 13 | Mar 27 – Apr 10 | — | — |
| Peppers | Feb 13 – Feb 27 | May 8 – May 22 | — | — |
| Eggplant | Feb 13 – Feb 27 | May 8 – May 22 | — | — |
| Tomatoes | Feb 27 – Mar 13 | May 1 – May 15 | — | — |
| Lettuce | Feb 27 – Mar 13 | Apr 3 – Apr 17 | Mar 27 – May 1 | Aug 19 – Sep 16 |
| Kale | Feb 27 – Mar 13 | Mar 27 – Apr 10 | Mar 27 – Apr 10 | Aug 5 – Aug 26 |
| Broccoli | Feb 27 – Mar 13 | Apr 10 – Apr 24 | — | Jul 8 – Jul 29 |
| Cabbage | Feb 27 – Mar 13 | Apr 3 – Apr 17 | — | Jul 8 – Jul 29 |
| Cauliflower | Feb 27 – Mar 13 | Apr 10 – Apr 24 | — | Jul 8 – Jul 29 |
| Okra | Mar 13 – Mar 27 | May 15 – May 29 | May 15 – May 29 | — |
| Basil | Mar 13 – Mar 27 | May 1 – May 15 | — | — |
| Peas | — | — | Mar 13 – Apr 3 | Jul 22 – Aug 12 |
| Spinach | — | — | Mar 13 – Apr 3 | Aug 19 – Sep 9 |
| Radishes | — | — | Mar 20 – May 1 | Sep 2 – Sep 23 |
| Cucumbers | Mar 27 – Apr 3 | May 8 – May 15 | May 1 – May 15 | Jul 29 – Aug 12 |
| Zucchini & Summer Squash | Mar 27 – Apr 3 | — | May 1 – May 15 | Aug 5 – Aug 19 |
| Winter Squash & Pumpkins | Mar 27 – Apr 3 | — | May 1 – May 15 | — |
| Melons & Watermelon | Mar 27 – Apr 3 | May 8 – May 22 | — | — |
| Carrots | — | — | Apr 3 – May 1 | Jul 22 – Aug 5 |
| Beets | — | — | Apr 3 – May 1 | Aug 5 – Aug 19 |
| Potatoes | — | — | Apr 3 – Apr 24 | — |
| Swiss Chard | — | — | Apr 10 – May 8 | Aug 5 – Aug 19 |
| Cilantro | — | — | Apr 10 – May 1 | Aug 19 – Sep 9 |
| Green Beans | — | — | May 1 – May 22 | Jul 29 – Aug 12 |
| Sweet Corn | — | — | May 1 – May 15 | — |
| Sweet Potatoes | — | May 8 – May 29 | — | — |
| Garlic | — | — | — | Sep 30 – Nov 4 |
Dates come from the median frost dates and common extension-service timing. Adjust for your soil temperature, microclimate and the varieties you grow.
About these dates
Based on 1991–2020 NOAA climate normals for the Eau Claire 3sw, WI weather station, 16 km away (elevation 879 ft (268 m)).
Frost dates near Rock Falls
- Elk Mound May 8 · Oct 4
- Eau Claire Apr 24 · Oct 14
- Downsville May 9 · Oct 1
- Eleva May 10 · Oct 2
- Durand May 1 · Oct 10
- Altoona Apr 24 · Oct 14
- Eau Galle May 1 · Oct 10
- Menomonie May 9 · Oct 1
- Mondovi May 10 · Oct 2
- Gilmanton May 10 · Oct 2
Frequently asked questions
When is the last frost in Rock Falls, WI?
The median last spring frost in Rock Falls, WI is April 24. There is still about a 10% chance of frost after May 7, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Rock Falls, WI?
The median first fall frost is October 14, with about a 10% chance of frost before September 26.
How long is the growing season in Rock Falls, WI?
About 173 days between the median last spring frost and first fall frost.
What planting zone is Rock Falls, WI?
Rock Falls, WI is in USDA hardiness zone 4b.