Frost dates for Washington Is, WI
When the last spring frost and first fall frost usually come, and when to plant, from 30 years of NOAA weather records.
Last spring frost
May 15
typical year
Safe to plant
May 31
frost is over in 9 of 10 years
First fall frost
October 14
typical year
Growing season
152 days
frost-free, typical year
Frost watch this week
Tonight's and the next six nights' lows from the National Weather Service forecast for the station's location. Frost: 32°F or colder. Possible frost: 33–36°F, mostly in low spots on clear, still nights.
When to plant
Counted from this page's frost dates. Warm-season crops wait for the safe-to-plant date.
| Crop | Start indoors | Plant outside | Fall planting |
|---|---|---|---|
| Cool-season crops | |||
| Peas | – | Apr 17 – May 1 | – |
| Spinach | – | Apr 3 – 24 | Aug 19 – Sep 2 |
| Lettuce | – | Apr 17 – May 8 | Aug 19 – Sep 2 |
| Radishes | – | Apr 17 – May 29 | Sep 2 – 16 |
| Onions | – | Apr 17 – May 1 | – |
| Potatoes | – | Apr 24 – May 8 | – |
| Carrots | – | Apr 24 – May 15 | Jul 22 – Aug 5 |
| Beets | – | Apr 17 – May 1 | Aug 5 – 19 |
| Kale | Mar 6 – 20 | Apr 17 – May 1 | Aug 5 – 19 |
| Broccoli | Mar 6 – 20 | May 1 – 15 | Aug 5 – 19 |
| Cabbage | Feb 20 – Mar 6 | Apr 17 – May 1 | Aug 5 – 19 |
| Garlic | – | – | Sep 2 – 23 |
| Warm-season crops | |||
| Tomatoes | Apr 5 – 19 | May 31 – Jun 14 | – |
| Peppers | Mar 29 – Apr 12 | Jun 7 – 21 | – |
| Cucumbers | – | May 31 – Jun 21 | – |
| Zucchini | – | May 31 – Jun 28 | – |
| Pumpkins | – | May 31 – Jun 21 | – |
| Green beans | – | May 31 – Aug 5 | – |
| Sweet corn | – | May 31 – Jun 28 | – |
| Basil | Apr 26 – May 10 | Jun 7 – 14 | – |
Onions: from sets. Green beans: until 10 weeks before the first fall frost. Garlic: harvest next summer.
The year at a glance
Start indoors Plant outside Fall planting
The chance of frost, by date
| 1 year in 10 | Half of years | 9 years in 10 | |
|---|---|---|---|
| Spring frost after | May 31 | May 15 | April 30 |
| Fall frost before | September 28 | October 14 | October 31 |
Frost here means 32°F or colder. Read across: in 1 year in 10, spring frost carries on past the first date, which is why that date is the safe-to-plant date.
Hard freeze (28°F)
A hard freeze kills most garden plants, even hardy ones. The last one in spring usually comes around May 3 (May 18 in a late year), and the first one in fall around October 28.
Where these dates come from
NOAA weather station WASHINGTON IS, WI US (USC00478905), 1991–2020 climate normals. It's the nearest station for 1 zip code, all within 1 miles:
54246
Planting dates follow common university extension advice; your local extension service can fine-tune them for your soil and microclimate.