Quinn, SD 57775 Frost Dates
57775, near Quinn, SD: the frost window
Typically, the last spring freeze lands around 05/11, roughly 256 days out. Fall's first freeze usually shows up around 09/30, roughly 141 days after the last spring frost.
Quinn 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
Quinn'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
05/11 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.
Quinn against the rest of the dataset
About 141 days separate Quinn's last and first frost, putting it 37,014 of 40,283 ZIP codes nationally. Within SD, it ranks 307 of 378.
Learn more
Two guides worth reading on 57775: local microclimates, on what one yard in Quinn can differ from the 57775 normal, and zone vs. frost date, on why Zone 5a and Quinn's frost date answer different questions.