Niagara, WI 49876 Frost Dates
49876, near Niagara, WI: the frost window
Around 05/17 is the usual last spring frost, about 262 days away. Fall's first freeze usually shows up around 10/01, roughly 135 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Niagara in Zone 4b (-25 to -20°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
Stretching the season past the first frost
Niagara's growing season runs out in roughly 5 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
How much risk comes with planting early here
05/17 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/02 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/31 and only about 1 year in 10 sees frost after that.
Niagara against the rest of the dataset
Niagara's growing season runs about 135 days, ranking 37,872 of 40,283 US ZIP codes measured here, longest to shortest. Within WI, it ranks 771 of 860.
Learn more
Two guides worth reading on 49876: local microclimates, on what one yard in Niagara can differ from the 49876 normal, and zone vs. frost date, on why Zone 4b and Niagara's frost date answer different questions.