Reliance, SD 57548 Frost Dates
57548, near Reliance, SD: the frost window
Typically, the last spring freeze lands around 05/10, roughly 255 days out. Fall's first freeze usually shows up around 09/29, roughly 140 days after the last spring frost.
Reliance sits in USDA Zone 4b (-25 to -20°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
Reliance'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 Reliance's last frost
05/10 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/29 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/24 and only about 1 year in 10 sees frost after that.
Reliance against the rest of the dataset
Reliance's growing season runs about 140 days, ranking 37,191 of 40,283 US ZIP codes measured here, longest to shortest. Within SD, it ranks 312 of 378.
Learn more
Two guides worth reading on 57548: zone vs. frost date, on why Zone 4b and Reliance's frost date answer different questions, and the frost range, on how to read the range around Reliance's dates instead of trusting one.