Herbster, WI frost dates
Last spring frostMay 31median date
First fall frostOct 2median date
Growing season124 daysfrost-free
Hardiness zone4bZone 4b
How Herbster compares
- In 8 years out of 10, the last spring frost in Herbster falls between May 16 and June 13, a 28-day window. The first fall frost falls between September 17 and October 14.
- The median last frost is 26 days later than the Wisconsin median of May 5.
- Its 124-day growing season is longer than 4% of the 749 Wisconsin places with a regular frost season (state median 155 days).
- The last frost is 23 days later 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 177 nights a year at or below 32°F.
- Compared with Duluth, MN, 68 km away, the last frost here is 17 days later than there and the growing season is 27 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 16 |
| 50% (median) | May 31 |
| 10% (safe for tender plants) | June 13 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 17 |
| 50% (median) | October 2 |
| 90% (late) | October 14 |
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 Herbster, WI
Herbster, WI frost dates — last frost May 31, first frost Oct 2, zone 4b. whenisthelastfrost.com
Crop
JFMAMJJASOND
Start indoors: Mar 8 to Mar 22Transplant outside: May 3 to May 17
Start indoors: Mar 22 to Apr 5Transplant outside: Jun 14 to Jun 28
Start indoors: Mar 22 to Apr 5Transplant outside: Jun 14 to Jun 28
Start indoors: Apr 5 to Apr 19Transplant outside: Jun 7 to Jun 21
Start indoors: Apr 5 to Apr 19Transplant outside: May 10 to May 24Sow outdoors: May 3 to Jun 7Plant for fall: Aug 7 to Sep 4
Start indoors: Apr 5 to Apr 19Transplant outside: May 3 to May 17Sow outdoors: May 3 to May 17Plant for fall: Jul 24 to Aug 14
Start indoors: Apr 5 to Apr 19Transplant outside: May 17 to May 31Plant for fall: Jun 26 to Jul 17
Start indoors: Apr 5 to Apr 19Transplant outside: May 10 to May 24Plant for fall: Jun 26 to Jul 17
Start indoors: Apr 5 to Apr 19Transplant outside: May 17 to May 31Plant for fall: Jun 26 to Jul 17
Start indoors: Apr 19 to May 3Transplant outside: Jun 21 to Jul 5Sow outdoors: Jun 21 to Jul 5
Start indoors: Apr 19 to May 3Transplant outside: Jun 7 to Jun 21
Sow outdoors: Apr 19 to May 10Plant for fall: Jul 10 to Jul 31
Sow outdoors: Apr 19 to May 10Plant for fall: Aug 7 to Aug 28
Sow outdoors: Apr 26 to Jun 7Plant for fall: Aug 21 to Sep 11
Start indoors: May 3 to May 10Transplant outside: Jun 14 to Jun 21Sow outdoors: Jun 7 to Jun 21Plant for fall: Jul 17 to Jul 31
Start indoors: May 3 to May 10Sow outdoors: Jun 7 to Jun 21Plant for fall: Jul 24 to Aug 7
Start indoors: May 3 to May 10Sow outdoors: Jun 7 to Jun 21
Start indoors: May 3 to May 10Transplant outside: Jun 14 to Jun 28
Sow outdoors: May 10 to Jun 7Plant for fall: Jul 10 to Jul 24
Sow outdoors: May 10 to Jun 7Plant for fall: Jul 24 to Aug 7
Sow outdoors: May 10 to May 31
Sow outdoors: May 17 to Jun 14Plant for fall: Jul 24 to Aug 7
Sow outdoors: May 17 to Jun 7Plant for fall: Aug 7 to Aug 28
Sow outdoors: Jun 7 to Jun 28Plant for fall: Jul 17 to Jul 31
Sow outdoors: Jun 7 to Jun 21
Transplant outside: Jun 14 to Jul 5
Plant for fall: Sep 18 to Oct 23
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Herbster, WI
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Mar 8 – Mar 22 | May 3 – May 17 | — | — |
| Peppers | Mar 22 – Apr 5 | Jun 14 – Jun 28 | — | — |
| Eggplant | Mar 22 – Apr 5 | Jun 14 – Jun 28 | — | — |
| Tomatoes | Apr 5 – Apr 19 | Jun 7 – Jun 21 | — | — |
| Lettuce | Apr 5 – Apr 19 | May 10 – May 24 | May 3 – Jun 7 | Aug 7 – Sep 4 |
| Kale | Apr 5 – Apr 19 | May 3 – May 17 | May 3 – May 17 | Jul 24 – Aug 14 |
| Broccoli | Apr 5 – Apr 19 | May 17 – May 31 | — | Jun 26 – Jul 17 |
| Cabbage | Apr 5 – Apr 19 | May 10 – May 24 | — | Jun 26 – Jul 17 |
| Cauliflower | Apr 5 – Apr 19 | May 17 – May 31 | — | Jun 26 – Jul 17 |
| Okra | Apr 19 – May 3 | Jun 21 – Jul 5 | Jun 21 – Jul 5 | — |
| Basil | Apr 19 – May 3 | Jun 7 – Jun 21 | — | — |
| Peas | — | — | Apr 19 – May 10 | Jul 10 – Jul 31 |
| Spinach | — | — | Apr 19 – May 10 | Aug 7 – Aug 28 |
| Radishes | — | — | Apr 26 – Jun 7 | Aug 21 – Sep 11 |
| Cucumbers | May 3 – May 10 | Jun 14 – Jun 21 | Jun 7 – Jun 21 | Jul 17 – Jul 31 |
| Zucchini & Summer Squash | May 3 – May 10 | — | Jun 7 – Jun 21 | Jul 24 – Aug 7 |
| Winter Squash & Pumpkins | May 3 – May 10 | — | Jun 7 – Jun 21 | — |
| Melons & Watermelon | May 3 – May 10 | Jun 14 – Jun 28 | — | — |
| Carrots | — | — | May 10 – Jun 7 | Jul 10 – Jul 24 |
| Beets | — | — | May 10 – Jun 7 | Jul 24 – Aug 7 |
| Potatoes | — | — | May 10 – May 31 | — |
| Swiss Chard | — | — | May 17 – Jun 14 | Jul 24 – Aug 7 |
| Cilantro | — | — | May 17 – Jun 7 | Aug 7 – Aug 28 |
| Green Beans | — | — | Jun 7 – Jun 28 | Jul 17 – Jul 31 |
| Sweet Corn | — | — | Jun 7 – Jun 21 | — |
| Sweet Potatoes | — | Jun 14 – Jul 5 | — | — |
| Garlic | — | — | — | Sep 18 – Oct 23 |
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 Port Wing, WI weather station, 13 km away (elevation 650 ft (198 m)).
Frost dates near Herbster
- Cornucopia May 23 · Oct 2
- Port Wing May 31 · Oct 2
- Washburn May 23 · Oct 2
- Iron River May 24 · Sep 26
- Bayfield May 20 · Oct 8
- Brule May 24 · Sep 26
- Benoit May 23 · Sep 29
- Maple May 24 · Sep 26
- Mason May 20 · Oct 1
- Ashland May 20 · Oct 2
Frequently asked questions
When is the last frost in Herbster, WI?
The median last spring frost in Herbster, WI is May 31. There is still about a 10% chance of frost after June 13, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Herbster, WI?
The median first fall frost is October 2, with about a 10% chance of frost before September 17.
How long is the growing season in Herbster, WI?
About 124 days between the median last spring frost and first fall frost.
What planting zone is Herbster, WI?
Herbster, WI is in USDA hardiness zone 4b.