Last spring frost
Apr 30
Frost Dates for Allouez, WI
First fall frost
Oct 9
Growing season
161 days
Hardiness zone
5b
In an average year around Allouez, WI, the last spring frost (32°F) is about Apr 30 and the first fall frost is about Oct 9, giving roughly a 161-day growing season. To be safe most years, wait until Apr 16 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 27 | May 13 | Apr 29 |
| Freeze (32°F) | May 16 | Apr 30 | Apr 16 |
| Hard (28°F) | May 4 | Apr 17 | Apr 3 |
| Severe (24°F) | Apr 21 | Apr 5 | Mar 22 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 27 | May 23 | May 19 | May 16 | May 13 | May 9 | May 6 | May 2 | Apr 29 |
| 32°F | May 16 | May 11 | May 7 | May 4 | Apr 30 | Apr 29 | Apr 25 | Apr 22 | Apr 16 |
| 28°F | May 4 | Apr 29 | Apr 24 | Apr 21 | Apr 17 | Apr 15 | Apr 11 | Apr 7 | Apr 3 |
| 24°F | Apr 21 | Apr 16 | Apr 12 | Apr 8 | Apr 5 | Apr 3 | Apr 1 | Mar 28 | Mar 22 |
| 20°F | Apr 11 | Apr 6 | Apr 3 | Mar 31 | Mar 29 | Mar 26 | Mar 22 | Mar 18 | Mar 13 |
| 16°F | Apr 4 | Mar 31 | Mar 27 | Mar 24 | Mar 20 | Mar 17 | Mar 14 | Mar 10 | Mar 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) | Sep 16 | Sep 29 | Oct 12 |
| Freeze (32°F) | Sep 24 | Oct 9 | Oct 26 |
| Hard (28°F) | Oct 6 | Oct 24 | Nov 9 |
| Severe (24°F) | Oct 21 | Nov 6 | Nov 22 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 16 | Sep 20 | Sep 24 | Sep 26 | Sep 29 | Oct 1 | Oct 4 | Oct 7 | Oct 12 |
| 32°F | Sep 24 | Sep 29 | Oct 3 | Oct 6 | Oct 9 | Oct 12 | Oct 16 | Oct 21 | Oct 26 |
| 28°F | Oct 6 | Oct 11 | Oct 16 | Oct 21 | Oct 24 | Oct 28 | Nov 1 | Nov 3 | Nov 9 |
| 24°F | Oct 21 | Oct 28 | Nov 1 | Nov 2 | Nov 6 | Nov 9 | Nov 12 | Nov 17 | Nov 22 |
| 20°F | Nov 1 | Nov 6 | Nov 10 | Nov 14 | Nov 17 | Nov 20 | Nov 23 | Nov 26 | Dec 1 |
| 16°F | Nov 10 | Nov 16 | Nov 19 | Nov 23 | Nov 25 | Nov 28 | Dec 1 | Dec 4 | Dec 10 |
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: Green Bay, Wi, about 4.1 miles away@if(!empty($station['elevation_ft'])), at 682 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 Allouez, WI?
On average, the last spring frost (32°F) around Allouez, WI is about Apr 30. In cooler years it can run later, so for a safer bet many gardeners wait until Apr 16.
When is the first frost in the fall?
The first fall frost around Allouez, WI typically arrives about Oct 9. 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 30 on average, or Apr 16 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 161 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 54307 Planting calendar → Wisconsin frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026