Eagle Butte, SD 57537 Frost Dates
57537, near Eagle Butte, SD: the frost window
Typically, the last spring freeze lands around 05/06, roughly 251 days out. Fall's first freeze usually shows up around 10/04, roughly 148 days after the last spring frost.
Zone 4b (-25 to -20°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 Eagle Butte, not a forecast for this year.
Stretching the season past the first frost
Eagle Butte'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 Eagle Butte's last frost
05/06 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/24 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/21 and only about 1 year in 10 sees frost after that.
Eagle Butte against the rest of the dataset
Eagle Butte's growing season runs about 148 days, ranking 35,737 of 40,283 US ZIP codes measured here, longest to shortest. Within SD, it ranks 197 of 378.
Learn more
Two guides worth reading on 57537: local microclimates, on what one yard in Eagle Butte can differ from the 57537 normal, and zone vs. frost date, on why Zone 4b and Eagle Butte's frost date answer different questions.