Lennox, SD 57039 Frost Dates
57039, near Lennox, SD: the frost window
Typically, the last spring freeze lands around 05/02, roughly 247 days out. Fall's first freeze usually shows up around 10/02, roughly 151 days after the last spring frost.
Lennox sits in USDA Zone 5a (-20 to -15°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
Stretching the season past the first frost
Lennox'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.
The actual range around Lennox's last frost
05/02 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/19 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.
Lennox against the rest of the dataset
At roughly 151 frost-free days, Lennox places 35,043 of 40,283 ZIP codes in this dataset. Within SD, it ranks 143 of 378.
Learn more
Two guides worth reading on 57039: the frost range, on how to read the range around Lennox's dates instead of trusting one, and local microclimates, on what one yard in Lennox can differ from the 57039 normal.