Oshkosh, WI 54902 Frost Dates
54902, near Oshkosh, WI: the frost window
Around 04/30 is the usual last spring frost, about 245 days away. Fall's first freeze usually shows up around 10/13, roughly 165 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Oshkosh in Zone 5b (-15 to -10°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
Oshkosh's growing season runs out in roughly 7 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
04/30 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/15 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/13 and only about 1 year in 10 sees frost after that.
Oshkosh against the rest of the dataset
About 165 days separate Oshkosh's last and first frost, putting it 30,496 of 40,283 ZIP codes nationally. Within WI, it ranks 191 of 860.
Learn more
Two guides worth reading on 54902: the frost range, on how to read the range around Oshkosh's dates instead of trusting one, and local microclimates, on what one yard in Oshkosh can differ from the 54902 normal.