Last spring frost
Apr 28
Frost Dates for Shabbona, IL
First fall frost
Oct 10
Growing season
163 days
Hardiness zone
5b
In an average year around Shabbona, IL, the last spring frost (32°F) is about Apr 28 and the first fall frost is about Oct 10, giving roughly a 163-day growing season. To be safe most years, wait until Apr 14 before setting out tender plants.
Last spring frost
Dates the last frost of spring typically ends. Plant tender crops after the risk has passed for your comfort level.
| Frost intensity | Early (10%) | Average (50%) | Late (90%) |
|---|---|---|---|
| Light (36°F) | May 23 | May 8 | Apr 23 |
| Freeze (32°F) | May 13 | Apr 28 | Apr 14 |
| Hard (28°F) | May 4 | Apr 17 | Apr 2 |
| Severe (24°F) | Apr 23 | Apr 4 | Mar 19 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 23 | May 18 | May 14 | May 11 | May 8 | May 4 | Apr 30 | Apr 28 | Apr 23 |
| 32°F | May 13 | May 8 | May 4 | Apr 30 | Apr 28 | Apr 25 | Apr 22 | Apr 18 | Apr 14 |
| 28°F | May 4 | Apr 28 | Apr 24 | Apr 21 | Apr 17 | Apr 14 | Apr 11 | Apr 7 | Apr 2 |
| 24°F | Apr 23 | Apr 18 | Apr 12 | Apr 8 | Apr 4 | Apr 2 | Mar 31 | Mar 25 | Mar 19 |
| 20°F | Apr 7 | Apr 2 | Mar 31 | Mar 27 | Mar 23 | Mar 20 | Mar 17 | Mar 12 | Mar 8 |
| 16°F | Mar 30 | Mar 24 | Mar 19 | Mar 16 | Mar 13 | Mar 10 | Mar 7 | Mar 4 | Feb 28 |
First fall frost
Dates the first frost of fall typically arrives. Count back by a crop's days-to-maturity to know your planting cutoff.
| Frost intensity | Early (10%) | Average (50%) | Late (90%) |
|---|---|---|---|
| Light (36°F) | Sep 17 | Sep 30 | Oct 13 |
| Freeze (32°F) | Sep 26 | Oct 10 | Oct 23 |
| Hard (28°F) | Oct 6 | Oct 21 | Nov 2 |
| Severe (24°F) | Oct 18 | Nov 1 | Nov 16 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 17 | Sep 22 | Sep 25 | Sep 28 | Sep 30 | Oct 2 | Oct 5 | Oct 8 | Oct 13 |
| 32°F | Sep 26 | Oct 1 | Oct 4 | Oct 7 | Oct 10 | Oct 13 | Oct 15 | Oct 19 | Oct 23 |
| 28°F | Oct 6 | Oct 11 | Oct 15 | Oct 18 | Oct 21 | Oct 23 | Oct 26 | Oct 29 | Nov 2 |
| 24°F | Oct 18 | Oct 24 | Oct 27 | Oct 30 | Nov 1 | Nov 3 | Nov 7 | Nov 10 | Nov 16 |
| 20°F | Oct 31 | Nov 2 | Nov 6 | Nov 9 | Nov 12 | Nov 15 | Nov 19 | Nov 23 | Nov 28 |
| 16°F | Nov 7 | Nov 12 | Nov 15 | Nov 18 | Nov 21 | Nov 25 | Nov 28 | Dec 1 | Dec 9 |
Growing season is measured at 32°F with about 50% probability. Hardiness zone from the 2023 USDA map; frost normals from NOAA 1991-2020.
Where this data comes from
@endif These dates are computed from the nearest official weather station with long-term records: Shabbona 5 Nne, Il, about 4.5 miles away@if(!empty($station['elevation_ft'])), at 861 ft elevation. The further the station and the greater the elevation difference from your yard, the more your local frost timing can vary.
How we calculate these dates
Frost and freeze dates come from the NOAA 1991–2020 U.S. Climate Normals, the National Oceanic and Atmospheric Administration's 30-year averages for each weather station. A date shown at the 50% level is the median: in half of years the frost falls on or before it. The 10% and 90% columns show the early and late ends of the range, so you can plant on the odds you're comfortable with. These are long-term averages, not a forecast for this year - always check your local outlook before planting.
Source: NOAA National Centers for Environmental Information, 1991–2020 Climate Normals (public domain). Harman is not affiliated with or endorsed by NOAA.
Frequently asked questions
When is the last frost in Shabbona, IL?
On average, the last spring frost (32°F) around Shabbona, IL is about Apr 28. In cooler years it can run later, so for a safer bet many gardeners wait until Apr 14.
When is the first frost in the fall?
The first fall frost around Shabbona, IL typically arrives about Oct 10. Count back by a crop's days to maturity to find the latest date you can plant it.
When can I plant tomatoes and other tender crops?
Tender crops like tomatoes, peppers and basil are damaged by frost, so wait until the last spring frost has passed - around Apr 28 on average, or Apr 14 to be safe most years.
How long is the growing season here?
The frost-free growing season (between the last spring and first fall 32°F frost) is about 163 days in a typical year.
Are these dates a forecast for this year?
No. They are 30-year averages from the NOAA 1991–2020 Climate Normals, not a prediction for the current year. Use them for planning and always check your local weather forecast before planting or protecting crops.
Local weather for 60550 Planting calendar → Illinois frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026