Last spring frost
Apr 26
Frost Dates for Milwaukee, WI
First fall frost
Oct 18
Growing season
173 days
Hardiness zone
5b
In an average year around Milwaukee, WI, the last spring frost (32°F) is about Apr 26 and the first fall frost is about Oct 18, giving roughly a 173-day growing season. To be safe most years, wait until Apr 12 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 24 | May 8 | Apr 24 |
| Freeze (32°F) | May 12 | Apr 26 | Apr 12 |
| Hard (28°F) | Apr 30 | Apr 14 | Apr 1 |
| Severe (24°F) | Apr 17 | Apr 4 | Mar 20 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 24 | May 19 | May 15 | May 11 | May 8 | May 5 | May 2 | Apr 30 | Apr 24 |
| 32°F | May 12 | May 6 | May 2 | Apr 29 | Apr 26 | Apr 23 | Apr 20 | Apr 16 | Apr 12 |
| 28°F | Apr 30 | Apr 24 | Apr 20 | Apr 16 | Apr 14 | Apr 11 | Apr 8 | Apr 5 | Apr 1 |
| 24°F | Apr 17 | Apr 12 | Apr 9 | Apr 6 | Apr 4 | Apr 2 | Mar 31 | Mar 27 | Mar 20 |
| 20°F | Apr 7 | Apr 3 | Mar 31 | Mar 28 | Mar 25 | Mar 22 | Mar 18 | Mar 15 | Mar 10 |
| 16°F | Mar 31 | Mar 25 | Mar 22 | Mar 18 | Mar 15 | Mar 12 | Mar 9 | Mar 6 | Mar 1 |
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 25 | Oct 6 | Oct 22 |
| Freeze (32°F) | Oct 2 | Oct 18 | Nov 1 |
| Hard (28°F) | Oct 13 | Oct 30 | Nov 11 |
| Severe (24°F) | Oct 27 | Nov 9 | Nov 23 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 25 | Sep 29 | Oct 2 | Oct 4 | Oct 6 | Oct 9 | Oct 12 | Oct 16 | Oct 22 |
| 32°F | Oct 2 | Oct 7 | Oct 12 | Oct 15 | Oct 18 | Oct 22 | Oct 24 | Oct 27 | Nov 1 |
| 28°F | Oct 13 | Oct 19 | Oct 23 | Oct 27 | Oct 30 | Nov 1 | Nov 3 | Nov 6 | Nov 11 |
| 24°F | Oct 27 | Nov 1 | Nov 3 | Nov 5 | Nov 9 | Nov 11 | Nov 14 | Nov 18 | Nov 23 |
| 20°F | Nov 4 | Nov 10 | Nov 12 | Nov 16 | Nov 19 | Nov 22 | Nov 25 | Nov 29 | Dec 4 |
| 16°F | Nov 12 | Nov 18 | Nov 21 | Nov 25 | Nov 27 | Dec 1 | Dec 4 | Dec 8 | Dec 16 |
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: Mt Mary College, Wi, about 6.3 miles away@if(!empty($station['elevation_ft'])), at 715 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 Milwaukee, WI?
On average, the last spring frost (32°F) around Milwaukee, WI is about Apr 26. In cooler years it can run later, so for a safer bet many gardeners wait until Apr 12.
When is the first frost in the fall?
The first fall frost around Milwaukee, WI typically arrives about Oct 18. 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 26 on average, or Apr 12 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 173 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 53224 Planting calendar → Wisconsin frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026