Frost dates for Zion, IL
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
April 30
typical year
Safe to plant
May 16
frost is over in 9 of 10 years
First fall frost
October 21
typical year
Growing season
173 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 2 – 16 | – |
| Spinach | – | Mar 19 – Apr 9 | Aug 26 – Sep 9 |
| Lettuce | – | Apr 2 – 23 | Aug 26 – Sep 9 |
| Radishes | – | Apr 2 – May 14 | Sep 9 – 23 |
| Onions | – | Apr 2 – 16 | – |
| Potatoes | – | Apr 9 – 23 | – |
| Carrots | – | Apr 9 – 30 | Jul 29 – Aug 12 |
| Beets | – | Apr 2 – 16 | Aug 12 – 26 |
| Kale | Feb 19 – Mar 5 | Apr 2 – 16 | Aug 12 – 26 |
| Broccoli | Feb 19 – Mar 5 | Apr 16 – 30 | Aug 12 – 26 |
| Cabbage | Feb 5 – 19 | Apr 2 – 16 | Aug 12 – 26 |
| Garlic | – | – | Sep 9 – 30 |
| Warm-season crops | |||
| Tomatoes | Mar 21 – Apr 4 | May 16 – 30 | – |
| Peppers | Mar 14 – 28 | May 23 – Jun 6 | – |
| Cucumbers | – | May 16 – Jun 6 | – |
| Zucchini | – | May 16 – Jun 13 | – |
| Pumpkins | – | May 16 – Jun 6 | – |
| Green beans | – | May 16 – Aug 12 | – |
| Sweet corn | – | May 16 – Jun 13 | – |
| Basil | Apr 11 – 25 | May 23 – 30 | – |
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 16 | April 30 | April 14 |
| Fall frost before | October 5 | October 21 | November 2 |
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 April 16 (May 2 in a late year), and the first one in fall around November 1.
Towns that use these dates
This is the nearest NOAA station with frost records for 4 towns.
Zion, Beach Park, Winthrop Harbor, Wadsworth
Where these dates come from
NOAA weather station CHICAGO WAUKEGAN RGNL AP, IL US (USW00014880), 1991–2020 climate normals. It's the nearest station for 5 zip codes, all within 6 miles:
60075, 60083, 60087, 60096, 60099
Planting dates follow common university extension advice; your local extension service can fine-tune them for your soil and microclimate.