Frost dates for Heyworth, 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 21
typical year
Safe to plant
May 5
frost is over in 9 of 10 years
First fall frost
October 20
typical year
Growing season
181 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 | – | Mar 24 – Apr 7 | – |
| Spinach | – | Mar 10 – 31 | Aug 25 – Sep 8 |
| Lettuce | – | Mar 24 – Apr 14 | Aug 25 – Sep 8 |
| Radishes | – | Mar 24 – May 5 | Sep 8 – 22 |
| Onions | – | Mar 24 – Apr 7 | – |
| Potatoes | – | Mar 31 – Apr 14 | – |
| Carrots | – | Mar 31 – Apr 21 | Jul 28 – Aug 11 |
| Beets | – | Mar 24 – Apr 7 | Aug 11 – 25 |
| Kale | Feb 10 – 24 | Mar 24 – Apr 7 | Aug 11 – 25 |
| Broccoli | Feb 10 – 24 | Apr 7 – 21 | Aug 11 – 25 |
| Cabbage | Jan 27 – Feb 10 | Mar 24 – Apr 7 | Aug 11 – 25 |
| Garlic | – | – | Sep 8 – 29 |
| Warm-season crops | |||
| Tomatoes | Mar 10 – 24 | May 5 – 19 | – |
| Peppers | Mar 3 – 17 | May 12 – 26 | – |
| Cucumbers | – | May 5 – 26 | – |
| Zucchini | – | May 5 – Jun 2 | – |
| Pumpkins | – | May 5 – 26 | – |
| Green beans | – | May 5 – Aug 11 | – |
| Sweet corn | – | May 5 – Jun 2 | – |
| Basil | Mar 31 – Apr 14 | May 12 – 19 | – |
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 5 | April 21 | April 7 |
| Fall frost before | October 9 | October 20 | November 1 |
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 9 (April 23 in a late year), and the first one in fall around October 30.
Towns that use these dates
This is the nearest NOAA station with frost records for 6 towns.
Heyworth, Minier, Danvers, McLean, Stanford, Wapella
Where these dates come from
NOAA weather station BLOOMINGTON 5W, IL US (USC00110764), 1991–2020 climate normals. It's the nearest station for 9 zip codes, all within 24 miles:
61701, 61705, 61735, 61745, 61754, 61759, 61772, 61774, 61777
Planting dates follow common university extension advice; your local extension service can fine-tune them for your soil and microclimate.