Last spring frost
Apr 7
Frost Dates for Cisne, IL
First fall frost
Oct 26
Growing season
201 days
Hardiness zone
6b
In an average year around Cisne, IL, the last spring frost (32°F) is about Apr 7 and the first fall frost is about Oct 26, giving roughly a 201-day growing season. To be safe most years, wait until Mar 23 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 6 | Apr 19 | Apr 4 |
| Freeze (32°F) | Apr 23 | Apr 7 | Mar 23 |
| Hard (28°F) | Apr 11 | Mar 27 | Mar 11 |
| Severe (24°F) | Mar 31 | Mar 15 | Feb 28 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 6 | May 1 | Apr 26 | Apr 23 | Apr 19 | Apr 17 | Apr 13 | Apr 9 | Apr 4 |
| 32°F | Apr 23 | Apr 18 | Apr 13 | Apr 10 | Apr 7 | Apr 3 | Apr 1 | Mar 29 | Mar 23 |
| 28°F | Apr 11 | Apr 5 | Apr 2 | Mar 30 | Mar 27 | Mar 24 | Mar 21 | Mar 17 | Mar 11 |
| 24°F | Mar 31 | Mar 27 | Mar 22 | Mar 18 | Mar 15 | Mar 12 | Mar 9 | Mar 5 | Feb 28 |
| 20°F | Mar 21 | Mar 16 | Mar 13 | Mar 9 | Mar 5 | Mar 2 | Feb 27 | Feb 22 | Feb 14 |
| 16°F | Mar 16 | Mar 9 | Mar 5 | Mar 1 | Feb 26 | Feb 20 | Feb 14 | Feb 8 | Feb 2 |
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) | Oct 3 | Oct 17 | Oct 29 |
| Freeze (32°F) | Oct 14 | Oct 26 | Nov 9 |
| Hard (28°F) | Oct 24 | Nov 6 | Nov 22 |
| Severe (24°F) | Nov 3 | Nov 17 | Dec 4 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 3 | Oct 9 | Oct 12 | Oct 15 | Oct 17 | Oct 19 | Oct 22 | Oct 25 | Oct 29 |
| 32°F | Oct 14 | Oct 19 | Oct 22 | Oct 24 | Oct 26 | Oct 29 | Oct 31 | Nov 4 | Nov 9 |
| 28°F | Oct 24 | Oct 30 | Nov 1 | Nov 4 | Nov 6 | Nov 8 | Nov 12 | Nov 16 | Nov 22 |
| 24°F | Nov 3 | Nov 7 | Nov 10 | Nov 14 | Nov 17 | Nov 21 | Nov 25 | Nov 30 | Dec 4 |
| 20°F | Nov 9 | Nov 15 | Nov 20 | Nov 24 | Nov 28 | Dec 1 | Dec 5 | Dec 10 | Dec 17 |
| 16°F | Nov 17 | Nov 25 | Dec 1 | Dec 4 | Dec 9 | Dec 14 | Dec 18 | Dec 23 | Jan 1 |
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: Fairfield Radio Wfiw, Il, about 11.2 miles away@if(!empty($station['elevation_ft'])), at 430 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 Cisne, IL?
On average, the last spring frost (32°F) around Cisne, IL is about Apr 7. In cooler years it can run later, so for a safer bet many gardeners wait until Mar 23.
When is the first frost in the fall?
The first fall frost around Cisne, IL typically arrives about Oct 26. 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 7 on average, or Mar 23 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 201 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 62823 Planting calendar → Illinois frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026