Jackson, WI frost dates
Last spring frostApr 30median date
First fall frostOct 15median date
Growing season168 daysfrost-free
Hardiness zone5bZone 5b
How Jackson compares
- In 8 years out of 10, the last spring frost in Jackson falls between April 15 and May 15, a 30-day window. The first fall frost falls between October 1 and October 29.
- The median last frost is 5 days earlier than the Wisconsin median of May 5.
- Its 168-day growing season is longer than 83% of the 749 Wisconsin places with a regular frost season (state median 155 days).
- The last frost is typical for zone 5b, where the median is May 1.
- The weather station records an average of 146 nights a year at or below 32°F.
- Compared with Milwaukee, WI, 35 km away, the last frost here is 4 days later than there and the growing season is 11 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 15 |
| 50% (median) | April 30 |
| 10% (safe for tender plants) | May 15 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 1 |
| 50% (median) | October 15 |
| 90% (late) | October 29 |
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 Jackson, WI
Jackson, WI frost dates — last frost Apr 30, first frost Oct 15, zone 5b. whenisthelastfrost.com
Crop
JFMAMJJASOND
Start indoors: Feb 5 to Feb 19Transplant outside: Apr 2 to Apr 16
Start indoors: Feb 19 to Mar 5Transplant outside: May 14 to May 28
Start indoors: Feb 19 to Mar 5Transplant outside: May 14 to May 28
Start indoors: Mar 5 to Mar 19Transplant outside: May 7 to May 21
Start indoors: Mar 5 to Mar 19Transplant outside: Apr 9 to Apr 23Sow outdoors: Apr 2 to May 7Plant for fall: Aug 20 to Sep 17
Start indoors: Mar 5 to Mar 19Transplant outside: Apr 2 to Apr 16Sow outdoors: Apr 2 to Apr 16Plant for fall: Aug 6 to Aug 27
Start indoors: Mar 5 to Mar 19Transplant outside: Apr 16 to Apr 30Plant for fall: Jul 9 to Jul 30
Start indoors: Mar 5 to Mar 19Transplant outside: Apr 9 to Apr 23Plant for fall: Jul 9 to Jul 30
Start indoors: Mar 5 to Mar 19Transplant outside: Apr 16 to Apr 30Plant for fall: Jul 9 to Jul 30
Start indoors: Mar 19 to Apr 2Transplant outside: May 21 to Jun 4Sow outdoors: May 21 to Jun 4
Start indoors: Mar 19 to Apr 2Transplant outside: May 7 to May 21
Sow outdoors: Mar 19 to Apr 9Plant for fall: Jul 23 to Aug 13
Sow outdoors: Mar 19 to Apr 9Plant for fall: Aug 20 to Sep 10
Sow outdoors: Mar 26 to May 7Plant for fall: Sep 3 to Sep 24
Start indoors: Apr 2 to Apr 9Transplant outside: May 14 to May 21Sow outdoors: May 7 to May 21Plant for fall: Jul 30 to Aug 13
Start indoors: Apr 2 to Apr 9Sow outdoors: May 7 to May 21Plant for fall: Aug 6 to Aug 20
Start indoors: Apr 2 to Apr 9Sow outdoors: May 7 to May 21
Start indoors: Apr 2 to Apr 9Transplant outside: May 14 to May 28
Sow outdoors: Apr 9 to May 7Plant for fall: Jul 23 to Aug 6
Sow outdoors: Apr 9 to May 7Plant for fall: Aug 6 to Aug 20
Sow outdoors: Apr 9 to Apr 30
Sow outdoors: Apr 16 to May 14Plant for fall: Aug 6 to Aug 20
Sow outdoors: Apr 16 to May 7Plant for fall: Aug 20 to Sep 10
Sow outdoors: May 7 to May 28Plant for fall: Jul 30 to Aug 13
Sow outdoors: May 7 to May 21
Transplant outside: May 14 to Jun 4
Plant for fall: Oct 1 to Nov 5
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Jackson, WI
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 5 – Feb 19 | Apr 2 – Apr 16 | — | — |
| Peppers | Feb 19 – Mar 5 | May 14 – May 28 | — | — |
| Eggplant | Feb 19 – Mar 5 | May 14 – May 28 | — | — |
| Tomatoes | Mar 5 – Mar 19 | May 7 – May 21 | — | — |
| Lettuce | Mar 5 – Mar 19 | Apr 9 – Apr 23 | Apr 2 – May 7 | Aug 20 – Sep 17 |
| Kale | Mar 5 – Mar 19 | Apr 2 – Apr 16 | Apr 2 – Apr 16 | Aug 6 – Aug 27 |
| Broccoli | Mar 5 – Mar 19 | Apr 16 – Apr 30 | — | Jul 9 – Jul 30 |
| Cabbage | Mar 5 – Mar 19 | Apr 9 – Apr 23 | — | Jul 9 – Jul 30 |
| Cauliflower | Mar 5 – Mar 19 | Apr 16 – Apr 30 | — | Jul 9 – Jul 30 |
| Okra | Mar 19 – Apr 2 | May 21 – Jun 4 | May 21 – Jun 4 | — |
| Basil | Mar 19 – Apr 2 | May 7 – May 21 | — | — |
| Peas | — | — | Mar 19 – Apr 9 | Jul 23 – Aug 13 |
| Spinach | — | — | Mar 19 – Apr 9 | Aug 20 – Sep 10 |
| Radishes | — | — | Mar 26 – May 7 | Sep 3 – Sep 24 |
| Cucumbers | Apr 2 – Apr 9 | May 14 – May 21 | May 7 – May 21 | Jul 30 – Aug 13 |
| Zucchini & Summer Squash | Apr 2 – Apr 9 | — | May 7 – May 21 | Aug 6 – Aug 20 |
| Winter Squash & Pumpkins | Apr 2 – Apr 9 | — | May 7 – May 21 | — |
| Melons & Watermelon | Apr 2 – Apr 9 | May 14 – May 28 | — | — |
| Carrots | — | — | Apr 9 – May 7 | Jul 23 – Aug 6 |
| Beets | — | — | Apr 9 – May 7 | Aug 6 – Aug 20 |
| Potatoes | — | — | Apr 9 – Apr 30 | — |
| Swiss Chard | — | — | Apr 16 – May 14 | Aug 6 – Aug 20 |
| Cilantro | — | — | Apr 16 – May 7 | Aug 20 – Sep 10 |
| Green Beans | — | — | May 7 – May 28 | Jul 30 – Aug 13 |
| Sweet Corn | — | — | May 7 – May 21 | — |
| Sweet Potatoes | — | May 14 – Jun 4 | — | — |
| Garlic | — | — | — | Oct 1 – Nov 5 |
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 Jackson, WI weather station, about 1 km away (elevation 902 ft (275 m)).
Frost dates near Jackson
- Richfield Apr 30 · Oct 15
- Slinger May 5 · Oct 5
- Hubertus Apr 30 · Oct 16
- West Bend May 1 · Oct 12
- Germantown May 6 · Oct 8
- Cedarburg Apr 23 · Oct 24
- Newburg May 4 · Oct 11
- Colgate Apr 30 · Oct 16
- Mequon Apr 23 · Oct 24
- Hartford May 8 · Oct 3
Frequently asked questions
When is the last frost in Jackson, WI?
The median last spring frost in Jackson, WI is April 30. There is still about a 10% chance of frost after May 15, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Jackson, WI?
The median first fall frost is October 15, with about a 10% chance of frost before October 1.
How long is the growing season in Jackson, WI?
About 168 days between the median last spring frost and first fall frost.
What planting zone is Jackson, WI?
Jackson, WI is in USDA hardiness zone 5b.