Waterloo, WI 53594 Frost Dates
53594, near Waterloo, WI: the frost window
The last spring frost here typically falls around 04/30, about 245 days from today. Fall's first freeze usually shows up around 10/09, roughly 163 days after the last spring frost.
Zone 5b (-15 to -10°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Waterloo, not a forecast for this year.
Stretching the season past the first frost
Waterloo's growing season runs out in roughly 6 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 04/30 isn't a guarantee
04/30 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/16 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/15 and only about 1 year in 10 sees frost after that.
Waterloo against the rest of the dataset
At roughly 163 frost-free days, Waterloo places 31,388 of 40,283 ZIP codes in this dataset. Within WI, it ranks 230 of 860.
Learn more
Two guides worth reading on 53594: zone vs. frost date, on why Zone 5b and Waterloo's frost date answer different questions, and the frost range, on how to read the range around Waterloo's dates instead of trusting one.