Harshaw, WI frost dates
Last spring frostMay 26median date
First fall frostSep 23median date
Growing season120 daysfrost-free
Hardiness zone4aZone 4a
How Harshaw compares
- In 8 years out of 10, the last spring frost in Harshaw falls between May 9 and June 8, a 30-day window. The first fall frost falls between September 5 and October 7.
- The median last frost is 21 days later than the Wisconsin median of May 5.
- Its 120-day growing season is among the shortest of the 749 Wisconsin places with a regular frost season.
- The last frost is 14 days later than the zone 4a median of May 12. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 4a chart.
- The weather station records an average of 185 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 9 |
| 50% (median) | May 26 |
| 10% (safe for tender plants) | June 8 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 5 |
| 50% (median) | September 23 |
| 90% (late) | October 7 |
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 Harshaw, WI
Harshaw, WI frost dates — last frost May 26, first frost Sep 23, zone 4a. whenisthelastfrost.com
Crop
JFMAMJJASOND
Start indoors: Mar 3 to Mar 17Transplant outside: Apr 28 to May 12
Start indoors: Mar 17 to Mar 31Transplant outside: Jun 9 to Jun 23
Start indoors: Mar 17 to Mar 31Transplant outside: Jun 9 to Jun 23
Start indoors: Mar 31 to Apr 14Transplant outside: Jun 2 to Jun 16
Start indoors: Mar 31 to Apr 14Transplant outside: May 5 to May 19Sow outdoors: Apr 28 to Jun 2Plant for fall: Jul 29 to Aug 26
Start indoors: Mar 31 to Apr 14Transplant outside: Apr 28 to May 12Sow outdoors: Apr 28 to May 12Plant for fall: Jul 15 to Aug 5
Start indoors: Mar 31 to Apr 14Transplant outside: May 12 to May 26Plant for fall: Jun 17 to Jul 8
Start indoors: Mar 31 to Apr 14Transplant outside: May 5 to May 19Plant for fall: Jun 17 to Jul 8
Start indoors: Mar 31 to Apr 14Transplant outside: May 12 to May 26Plant for fall: Jun 17 to Jul 8
Start indoors: Apr 14 to Apr 28Transplant outside: Jun 16 to Jun 30Sow outdoors: Jun 16 to Jun 30
Start indoors: Apr 14 to Apr 28Transplant outside: Jun 2 to Jun 16
Sow outdoors: Apr 14 to May 5Plant for fall: Jul 1 to Jul 22
Sow outdoors: Apr 14 to May 5Plant for fall: Jul 29 to Aug 19
Sow outdoors: Apr 21 to Jun 2Plant for fall: Aug 12 to Sep 2
Start indoors: Apr 28 to May 5Transplant outside: Jun 9 to Jun 16Sow outdoors: Jun 2 to Jun 16Plant for fall: Jul 8 to Jul 22
Start indoors: Apr 28 to May 5Sow outdoors: Jun 2 to Jun 16Plant for fall: Jul 15 to Jul 29
Start indoors: Apr 28 to May 5Sow outdoors: Jun 2 to Jun 16
Start indoors: Apr 28 to May 5Transplant outside: Jun 9 to Jun 23
Sow outdoors: May 5 to Jun 2Plant for fall: Jul 1 to Jul 15
Sow outdoors: May 5 to Jun 2Plant for fall: Jul 15 to Jul 29
Sow outdoors: May 5 to May 26
Sow outdoors: May 12 to Jun 9Plant for fall: Jul 15 to Jul 29
Sow outdoors: May 12 to Jun 2Plant for fall: Jul 29 to Aug 19
Sow outdoors: Jun 2 to Jun 23Plant for fall: Jul 8 to Jul 22
Sow outdoors: Jun 2 to Jun 16
Transplant outside: Jun 9 to Jun 30
Plant for fall: Sep 9 to Oct 14
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Harshaw, WI
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Mar 3 – Mar 17 | Apr 28 – May 12 | — | — |
| Peppers | Mar 17 – Mar 31 | Jun 9 – Jun 23 | — | — |
| Eggplant | Mar 17 – Mar 31 | Jun 9 – Jun 23 | — | — |
| Tomatoes | Mar 31 – Apr 14 | Jun 2 – Jun 16 | — | — |
| Lettuce | Mar 31 – Apr 14 | May 5 – May 19 | Apr 28 – Jun 2 | Jul 29 – Aug 26 |
| Kale | Mar 31 – Apr 14 | Apr 28 – May 12 | Apr 28 – May 12 | Jul 15 – Aug 5 |
| Broccoli | Mar 31 – Apr 14 | May 12 – May 26 | — | Jun 17 – Jul 8 |
| Cabbage | Mar 31 – Apr 14 | May 5 – May 19 | — | Jun 17 – Jul 8 |
| Cauliflower | Mar 31 – Apr 14 | May 12 – May 26 | — | Jun 17 – Jul 8 |
| Okra | Apr 14 – Apr 28 | Jun 16 – Jun 30 | Jun 16 – Jun 30 | — |
| Basil | Apr 14 – Apr 28 | Jun 2 – Jun 16 | — | — |
| Peas | — | — | Apr 14 – May 5 | Jul 1 – Jul 22 |
| Spinach | — | — | Apr 14 – May 5 | Jul 29 – Aug 19 |
| Radishes | — | — | Apr 21 – Jun 2 | Aug 12 – Sep 2 |
| Cucumbers | Apr 28 – May 5 | Jun 9 – Jun 16 | Jun 2 – Jun 16 | Jul 8 – Jul 22 |
| Zucchini & Summer Squash | Apr 28 – May 5 | — | Jun 2 – Jun 16 | Jul 15 – Jul 29 |
| Winter Squash & Pumpkins | Apr 28 – May 5 | — | Jun 2 – Jun 16 | — |
| Melons & Watermelon | Apr 28 – May 5 | Jun 9 – Jun 23 | — | — |
| Carrots | — | — | May 5 – Jun 2 | Jul 1 – Jul 15 |
| Beets | — | — | May 5 – Jun 2 | Jul 15 – Jul 29 |
| Potatoes | — | — | May 5 – May 26 | — |
| Swiss Chard | — | — | May 12 – Jun 9 | Jul 15 – Jul 29 |
| Cilantro | — | — | May 12 – Jun 2 | Jul 29 – Aug 19 |
| Green Beans | — | — | Jun 2 – Jun 23 | Jul 8 – Jul 22 |
| Sweet Corn | — | — | Jun 2 – Jun 16 | — |
| Sweet Potatoes | — | Jun 9 – Jun 30 | — | — |
| Garlic | — | — | — | Sep 9 – Oct 14 |
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 Rhinelander Oneida Ap, WI weather station, 15 km away (elevation 1,598 ft (487 m)).
Frost dates near Harshaw
- Mc Naughton May 26 · Sep 23
- Hazelhurst May 13 · Oct 3
- Lake Tomahawk May 19 · Oct 3
- Heafford Junction May 10 · Oct 4
- Rhinelander May 23 · Sep 23
- Tomahawk May 10 · Oct 4
- Minocqua May 23 · Sep 27
- Woodruff May 23 · Sep 27
- Tripoli May 13 · Oct 3
- Saint Germain May 19 · Oct 3
Frequently asked questions
When is the last frost in Harshaw, WI?
The median last spring frost in Harshaw, WI is May 26. There is still about a 10% chance of frost after June 8, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Harshaw, WI?
The median first fall frost is September 23, with about a 10% chance of frost before September 5.
How long is the growing season in Harshaw, WI?
About 120 days between the median last spring frost and first fall frost.
What planting zone is Harshaw, WI?
Harshaw, WI is in USDA hardiness zone 4a.