Dunbar, WI frost dates
Last spring frostMay 24median date
First fall frostSep 30median date
Growing season129 daysfrost-free
Hardiness zone4bZone 4b
How Dunbar compares
- In 8 years out of 10, the last spring frost in Dunbar falls between May 10 and June 7, a 28-day window. The first fall frost falls between September 16 and October 12.
- The median last frost is 19 days later than the Wisconsin median of May 5.
- Its 129-day growing season is longer than 8% of the 749 Wisconsin places with a regular frost season (state median 155 days).
- The last frost is 16 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 186 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 10 |
| 50% (median) | May 24 |
| 10% (safe for tender plants) | June 7 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 16 |
| 50% (median) | September 30 |
| 90% (late) | October 12 |
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 Dunbar, WI
Dunbar, WI frost dates — last frost May 24, first frost Sep 30, zone 4b. whenisthelastfrost.com
Crop
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Start indoors: Mar 1 to Mar 15Transplant outside: Apr 26 to May 10
Start indoors: Mar 15 to Mar 29Transplant outside: Jun 7 to Jun 21
Start indoors: Mar 15 to Mar 29Transplant outside: Jun 7 to Jun 21
Start indoors: Mar 29 to Apr 12Transplant outside: May 31 to Jun 14
Start indoors: Mar 29 to Apr 12Transplant outside: May 3 to May 17Sow outdoors: Apr 26 to May 31Plant for fall: Aug 5 to Sep 2
Start indoors: Mar 29 to Apr 12Transplant outside: Apr 26 to May 10Sow outdoors: Apr 26 to May 10Plant for fall: Jul 22 to Aug 12
Start indoors: Mar 29 to Apr 12Transplant outside: May 10 to May 24Plant for fall: Jun 24 to Jul 15
Start indoors: Mar 29 to Apr 12Transplant outside: May 3 to May 17Plant for fall: Jun 24 to Jul 15
Start indoors: Mar 29 to Apr 12Transplant outside: May 10 to May 24Plant for fall: Jun 24 to Jul 15
Start indoors: Apr 12 to Apr 26Transplant outside: Jun 14 to Jun 28Sow outdoors: Jun 14 to Jun 28
Start indoors: Apr 12 to Apr 26Transplant outside: May 31 to Jun 14
Sow outdoors: Apr 12 to May 3Plant for fall: Jul 8 to Jul 29
Sow outdoors: Apr 12 to May 3Plant for fall: Aug 5 to Aug 26
Sow outdoors: Apr 19 to May 31Plant for fall: Aug 19 to Sep 9
Start indoors: Apr 26 to May 3Transplant outside: Jun 7 to Jun 14Sow outdoors: May 31 to Jun 14Plant for fall: Jul 15 to Jul 29
Start indoors: Apr 26 to May 3Sow outdoors: May 31 to Jun 14Plant for fall: Jul 22 to Aug 5
Start indoors: Apr 26 to May 3Sow outdoors: May 31 to Jun 14
Start indoors: Apr 26 to May 3Transplant outside: Jun 7 to Jun 21
Sow outdoors: May 3 to May 31Plant for fall: Jul 8 to Jul 22
Sow outdoors: May 3 to May 31Plant for fall: Jul 22 to Aug 5
Sow outdoors: May 3 to May 24
Sow outdoors: May 10 to Jun 7Plant for fall: Jul 22 to Aug 5
Sow outdoors: May 10 to May 31Plant for fall: Aug 5 to Aug 26
Sow outdoors: May 31 to Jun 21Plant for fall: Jul 15 to Jul 29
Sow outdoors: May 31 to Jun 14
Transplant outside: Jun 7 to Jun 28
Plant for fall: Sep 16 to Oct 21
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Dunbar, WI
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Mar 1 – Mar 15 | Apr 26 – May 10 | — | — |
| Peppers | Mar 15 – Mar 29 | Jun 7 – Jun 21 | — | — |
| Eggplant | Mar 15 – Mar 29 | Jun 7 – Jun 21 | — | — |
| Tomatoes | Mar 29 – Apr 12 | May 31 – Jun 14 | — | — |
| Lettuce | Mar 29 – Apr 12 | May 3 – May 17 | Apr 26 – May 31 | Aug 5 – Sep 2 |
| Kale | Mar 29 – Apr 12 | Apr 26 – May 10 | Apr 26 – May 10 | Jul 22 – Aug 12 |
| Broccoli | Mar 29 – Apr 12 | May 10 – May 24 | — | Jun 24 – Jul 15 |
| Cabbage | Mar 29 – Apr 12 | May 3 – May 17 | — | Jun 24 – Jul 15 |
| Cauliflower | Mar 29 – Apr 12 | May 10 – May 24 | — | Jun 24 – Jul 15 |
| Okra | Apr 12 – Apr 26 | Jun 14 – Jun 28 | Jun 14 – Jun 28 | — |
| Basil | Apr 12 – Apr 26 | May 31 – Jun 14 | — | — |
| Peas | — | — | Apr 12 – May 3 | Jul 8 – Jul 29 |
| Spinach | — | — | Apr 12 – May 3 | Aug 5 – Aug 26 |
| Radishes | — | — | Apr 19 – May 31 | Aug 19 – Sep 9 |
| Cucumbers | Apr 26 – May 3 | Jun 7 – Jun 14 | May 31 – Jun 14 | Jul 15 – Jul 29 |
| Zucchini & Summer Squash | Apr 26 – May 3 | — | May 31 – Jun 14 | Jul 22 – Aug 5 |
| Winter Squash & Pumpkins | Apr 26 – May 3 | — | May 31 – Jun 14 | — |
| Melons & Watermelon | Apr 26 – May 3 | Jun 7 – Jun 21 | — | — |
| Carrots | — | — | May 3 – May 31 | Jul 8 – Jul 22 |
| Beets | — | — | May 3 – May 31 | Jul 22 – Aug 5 |
| Potatoes | — | — | May 3 – May 24 | — |
| Swiss Chard | — | — | May 10 – Jun 7 | Jul 22 – Aug 5 |
| Cilantro | — | — | May 10 – May 31 | Aug 5 – Aug 26 |
| Green Beans | — | — | May 31 – Jun 21 | Jul 15 – Jul 29 |
| Sweet Corn | — | — | May 31 – Jun 14 | — |
| Sweet Potatoes | — | Jun 7 – Jun 28 | — | — |
| Garlic | — | — | — | Sep 16 – Oct 21 |
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 Goodman Sanitary Dist, WI weather station, 20 km away (elevation 1,447 ft (441 m)).
Frost dates near Dunbar
- Pembine May 17 · Oct 1
- Amberg May 22 · Sep 27
- Niagara May 17 · Oct 1
- Athelstane May 26 · Sep 22
- Goodman May 24 · Sep 30
- Fence May 24 · Sep 30
- Armstrong Creek May 24 · Sep 30
- Wausaukee May 22 · Sep 27
- Florence May 24 · Sep 25
- Crivitz May 26 · Sep 22
Frequently asked questions
When is the last frost in Dunbar, WI?
The median last spring frost in Dunbar, WI is May 24. There is still about a 10% chance of frost after June 7, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Dunbar, WI?
The median first fall frost is September 30, with about a 10% chance of frost before September 16.
How long is the growing season in Dunbar, WI?
About 129 days between the median last spring frost and first fall frost.
What planting zone is Dunbar, WI?
Dunbar, WI is in USDA hardiness zone 4b.