Last spring frost
Apr 12
Frost Dates for Bridgeport, IL
First fall frost
Oct 25
Growing season
193 days
Hardiness zone
6b
In an average year around Bridgeport, IL, the last spring frost (32°F) is about Apr 12 and the first fall frost is about Oct 25, giving roughly a 193-day growing season. To be safe most years, wait until Mar 31 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 10 | Apr 24 | Apr 11 |
| Freeze (32°F) | Apr 30 | Apr 12 | Mar 31 |
| Hard (28°F) | Apr 17 | Apr 1 | Mar 17 |
| Severe (24°F) | Apr 5 | Mar 22 | Mar 3 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 10 | May 6 | May 1 | Apr 28 | Apr 24 | Apr 21 | Apr 18 | Apr 15 | Apr 11 |
| 32°F | Apr 30 | Apr 23 | Apr 19 | Apr 15 | Apr 12 | Apr 9 | Apr 6 | Apr 3 | Mar 31 |
| 28°F | Apr 17 | Apr 11 | Apr 6 | Apr 3 | Apr 1 | Mar 31 | Mar 27 | Mar 22 | Mar 17 |
| 24°F | Apr 5 | Apr 1 | Mar 30 | Mar 26 | Mar 22 | Mar 19 | Mar 15 | Mar 10 | Mar 3 |
| 20°F | Mar 29 | Mar 23 | Mar 18 | Mar 15 | Mar 12 | Mar 8 | Mar 3 | Feb 27 | Feb 18 |
| 16°F | Mar 19 | Mar 14 | Mar 9 | Mar 5 | Mar 1 | Feb 25 | Feb 20 | Feb 14 | Feb 6 |
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 2 | Oct 16 | Oct 27 |
| Freeze (32°F) | Oct 12 | Oct 25 | Nov 5 |
| Hard (28°F) | Oct 22 | Nov 3 | Nov 20 |
| Severe (24°F) | Oct 31 | Nov 14 | Dec 3 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 2 | Oct 7 | Oct 10 | Oct 13 | Oct 16 | Oct 18 | Oct 20 | Oct 24 | Oct 27 |
| 32°F | Oct 12 | Oct 17 | Oct 20 | Oct 23 | Oct 25 | Oct 28 | Oct 30 | Nov 2 | Nov 5 |
| 28°F | Oct 22 | Oct 26 | Oct 30 | Nov 1 | Nov 3 | Nov 6 | Nov 9 | Nov 13 | Nov 20 |
| 24°F | Oct 31 | Nov 4 | Nov 7 | Nov 11 | Nov 14 | Nov 18 | Nov 22 | Nov 27 | Dec 3 |
| 20°F | Nov 8 | Nov 14 | Nov 19 | Nov 23 | Nov 27 | Dec 1 | Dec 4 | Dec 8 | Dec 15 |
| 16°F | Nov 17 | Nov 25 | Nov 30 | Dec 3 | Dec 7 | Dec 11 | Dec 17 | Dec 21 | Dec 28 |
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: Lawrenceville 2Wsw, Il, about 2.9 miles away@if(!empty($station['elevation_ft'])), at 451 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 Bridgeport, IL?
On average, the last spring frost (32°F) around Bridgeport, IL is about Apr 12. In cooler years it can run later, so for a safer bet many gardeners wait until Mar 31.
When is the first frost in the fall?
The first fall frost around Bridgeport, IL typically arrives about Oct 25. 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 12 on average, or Mar 31 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 193 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 62417 Planting calendar → Illinois frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026