Milwaukee, WI Frost Dates: Last Spring and First Fall Frost

In a typical year the final freeze of spring reaches Milwaukee around April 26, and the first freeze of autumn returns around October 18. NOAA's normals call the frost-free stretch between them 173 days long.

Put May 12 and October 2 on the calendar as well. A spring freeze after the first of them, or a fall freeze before the second, happens in only one year out of ten, so those dates cover nine years in ten. Against the 100-city median of 229 days, Milwaukee has 56 days less room before frost returns.

These dates come from the NOAA weather station Mt Mary College (ID USC00475474), 3.2 miles west of the Census Bureau's internal point for Milwaukee, at about 710 feet above sea level.

Last spring frost in Milwaukee

Frost is still possible on April 12 in nine springs out of ten and on April 26 in five; only one spring in ten sees a freeze as late as May 12.

The early and late dates sit just 30 days apart, narrower than for most cities on these pages. Spring in Milwaukee rarely surprises by much.

First fall frost in Milwaukee

In Milwaukee the first freeze has arrived by October 2 in one fall out of ten, by October 18 in five, and by November 1 in nine.

Fall dates in Milwaukee spread over 30 days, about the same as the middle of the 100 cities on these pages.

The growing season in Milwaukee

The season is somewhat shorter than the middle of these pages, so a seed packet's days to maturity deserve a second look. There is little difference between a typical season (173 days) and a short one (153 days) in Milwaukee: 20 days, less than in most of the cities covered here.

NOAA counts these days from its own simulations, so they will not equal the number of days between the two typical dates exactly. A night at or below 32°F happens in 100% of years at this station, so frost is a yearly event here.

When a hard freeze reaches Milwaukee

Hard freezes trail the light ones by 12 days in fall (October 30 against October 18) and by 12 days in spring (April 14 against April 26). At the edges, a 28°F night on or after April 30 happens one spring in ten and one by October 13 one fall in ten; the nine-in-ten dates are April 1 and November 11.

What this means for planting in Milwaukee

In Milwaukee the University of New Hampshire Extension count lands like this, measured from the typical last frost on April 26: lettuce from March 29 to April 5, cabbage on March 29, seed potatoes from April 12 to April 19, then peppers on May 10 and beans from April 26. Peas are the exception to the count: University of New Hampshire Extension says to plant them as soon as the soil thaws, whatever the frost date.

From the late date, May 12, every tender crop moves back 16 days; that buys protection against a spring only one year in ten brings.

Milwaukee's first frost leaves room for only 25 of the 34 fall crops, counting back NC State Extension's days to harvest and University of Georgia Extension's harvest allowance of 18 days; for the other 9 the last planting day falls before July. Of the crops that fit, cabbage is the slowest: 93 days from planting to the early frost, which makes July 1 its last day.

Worked example: a tomato plan for Milwaukee

Suppose you want tomatoes in Milwaukee. University of New Hampshire Extension says to set transplants out one to two weeks after the last frost. Counting from the typical date, April 26, the window runs from May 3 to May 10. Counting from the late date, May 12, it moves to May 19 through May 26, which is 16 days later.

Seeds start six to eight weeks before the set-out day, so counting back from the first day of the late window gives March 24 to April 7 for sowing indoors.

From the last set-out day to the early first frost on October 2 is 129 days. NC State Extension gives 75 to 85 days, and the longer figure still fits with 44 days to spare.

The weather station behind these dates

3.2 miles west of the city's internal point, the station is close but not on top of Milwaukee.

At about 710 feet, it ranks above 56 and below 43 of the 100 stations used for these pages. Its completeness flag is S, which NOAA uses for a standard record.

The Census Gazetteer gives no elevation for Milwaukee itself, so this page cannot tell you whether your garden sits above or below the station. If it is noticeably higher or lower, compare the stations the frost dates tool lists nearby and lean toward the colder reading.

Milwaukee compared with nearby cities

Of the cities on these pages, Madison, WI is closest to Milwaukee at 74 miles, with two more farther out; none is a close neighbor.

• Madison, WI, 74 miles to the west: last frost May 1, first frost October 9, 161 days frost-free; its last frost comes 5 days after Milwaukee's, and the frost-free season is 12 days shorter than Milwaukee's.
• Chicago, IL lies 86 miles south of Milwaukee. Typical last frost April 10, first frost November 5, 208 days between; its last frost comes 16 days before Milwaukee's, and it has 35 days more without frost.
• Fort Wayne, IN, 199 miles to the south-east: last frost April 24, first frost October 21, 178 days frost-free; its last frost falls within a few days of Milwaukee's, and frost-free days differ from Milwaukee's by less than a week.

Next steps for Milwaukee gardeners

Start with the spring planting planner for the whole crop list counted from these dates, and the fall planting planner for the last planting days. The frost dates tool shows every level of risk at this station, and the hardiness zone lookup covers winter survival for shrubs and perennials.

Every city covered is on the city frost dates index, sorted by state.

Where these numbers come from

NOAA's U.S. Climate Normals for 1991–2020 (doi:10.25921/4ek7-fk11) supply every frost date here, unchanged from the station's record, and NOAA's documentation defines the probabilities. The Census Bureau's 2024 Gazetteer places Milwaukee on the map, and its Vintage 2024 estimates, 563,531 people here, decide which cities get a page.

Planting dates here are those rules from University of New Hampshire Extension, NC State Extension and University of Georgia Extension, applied to this station's frost dates and nothing else. See how we source every figure for the checks behind them.

Frost dates are long-term odds, not a forecast. Before you plant, check the local forecast for the coming week, and keep row cover or old sheets handy for the nights the odds get wrong.