Plain, WI frost dates
Last spring frostApr 30median date
First fall frostOct 9median date
Growing season162 daysfrost-free
Hardiness zone5aZone 5a
How Plain compares
- In 8 years out of 10, the last spring frost in Plain falls between April 15 and May 14, a 29-day window. The first fall frost falls between September 25 and October 21.
- The median last frost is 5 days earlier than the Wisconsin median of May 5.
- Its 162-day growing season is longer than 67% of the 749 Wisconsin places with a regular frost season (state median 155 days).
- The last frost is typical for zone 5a, where the median is May 3.
- The weather station records an average of 151 nights a year at or below 32°F.
- Compared with Madison, WI, 58 km away, the last frost here is 1 day earlier than there and the growing season is 1 day longer.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 15 |
| 50% (median) | April 30 |
| 10% (safe for tender plants) | May 14 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 25 |
| 50% (median) | October 9 |
| 90% (late) | October 21 |
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 Plain, WI
Plain, WI frost dates — last frost Apr 30, first frost Oct 9, zone 5a. whenisthelastfrost.com
Crop
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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 14 to Sep 11
Start indoors: Mar 5 to Mar 19Transplant outside: Apr 2 to Apr 16Sow outdoors: Apr 2 to Apr 16Plant for fall: Jul 31 to Aug 21
Start indoors: Mar 5 to Mar 19Transplant outside: Apr 16 to Apr 30Plant for fall: Jul 3 to Jul 24
Start indoors: Mar 5 to Mar 19Transplant outside: Apr 9 to Apr 23Plant for fall: Jul 3 to Jul 24
Start indoors: Mar 5 to Mar 19Transplant outside: Apr 16 to Apr 30Plant for fall: Jul 3 to Jul 24
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 17 to Aug 7
Sow outdoors: Mar 19 to Apr 9Plant for fall: Aug 14 to Sep 4
Sow outdoors: Mar 26 to May 7Plant for fall: Aug 28 to Sep 18
Start indoors: Apr 2 to Apr 9Transplant outside: May 14 to May 21Sow outdoors: May 7 to May 21Plant for fall: Jul 24 to Aug 7
Start indoors: Apr 2 to Apr 9Sow outdoors: May 7 to May 21Plant for fall: Jul 31 to Aug 14
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 17 to Jul 31
Sow outdoors: Apr 9 to May 7Plant for fall: Jul 31 to Aug 14
Sow outdoors: Apr 9 to Apr 30
Sow outdoors: Apr 16 to May 14Plant for fall: Jul 31 to Aug 14
Sow outdoors: Apr 16 to May 7Plant for fall: Aug 14 to Sep 4
Sow outdoors: May 7 to May 28Plant for fall: Jul 24 to Aug 7
Sow outdoors: May 7 to May 21
Transplant outside: May 14 to Jun 4
Plant for fall: Sep 25 to Oct 30
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Plain, 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 14 – Sep 11 |
| Kale | Mar 5 – Mar 19 | Apr 2 – Apr 16 | Apr 2 – Apr 16 | Jul 31 – Aug 21 |
| Broccoli | Mar 5 – Mar 19 | Apr 16 – Apr 30 | — | Jul 3 – Jul 24 |
| Cabbage | Mar 5 – Mar 19 | Apr 9 – Apr 23 | — | Jul 3 – Jul 24 |
| Cauliflower | Mar 5 – Mar 19 | Apr 16 – Apr 30 | — | Jul 3 – Jul 24 |
| 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 17 – Aug 7 |
| Spinach | — | — | Mar 19 – Apr 9 | Aug 14 – Sep 4 |
| Radishes | — | — | Mar 26 – May 7 | Aug 28 – Sep 18 |
| Cucumbers | Apr 2 – Apr 9 | May 14 – May 21 | May 7 – May 21 | Jul 24 – Aug 7 |
| Zucchini & Summer Squash | Apr 2 – Apr 9 | — | May 7 – May 21 | Jul 31 – Aug 14 |
| 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 17 – Jul 31 |
| Beets | — | — | Apr 9 – May 7 | Jul 31 – Aug 14 |
| Potatoes | — | — | Apr 9 – Apr 30 | — |
| Swiss Chard | — | — | Apr 16 – May 14 | Jul 31 – Aug 14 |
| Cilantro | — | — | Apr 16 – May 7 | Aug 14 – Sep 4 |
| Green Beans | — | — | May 7 – May 28 | Jul 24 – Aug 7 |
| Sweet Corn | — | — | May 7 – May 21 | — |
| Sweet Potatoes | — | May 14 – Jun 4 | — | — |
| Garlic | — | — | — | Sep 25 – Oct 30 |
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 Lone Rock Tri Co Ap, WI weather station, 14 km away (elevation 719 ft (219 m)).
Frost dates near Plain
- Spring Green Apr 30 · Oct 9
- Loganville Apr 24 · Oct 20
- Hillpoint Apr 24 · Oct 20
- Lone Rock Apr 30 · Oct 9
- Arena May 7 · Oct 1
- Sextonville May 5 · Oct 6
- Reedsburg Apr 24 · Oct 20
- Gotham Apr 30 · Oct 9
- Lime Ridge May 2 · Oct 7
- North Freedom Apr 24 · Oct 20
Frequently asked questions
When is the last frost in Plain, WI?
The median last spring frost in Plain, WI is April 30. There is still about a 10% chance of frost after May 14, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Plain, WI?
The median first fall frost is October 9, with about a 10% chance of frost before September 25.
How long is the growing season in Plain, WI?
About 162 days between the median last spring frost and first fall frost.
What planting zone is Plain, WI?
Plain, WI is in USDA hardiness zone 5a.