Timber Lake, SD 57656 Frost Dates
57656, near Timber Lake, 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 09/30, roughly 141 days after the last spring frost.
Timber Lake 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
Timber Lake'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.
Why 05/10 isn't a guarantee
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 05/23 and only about 1 year in 10 sees frost after that.
Timber Lake against the rest of the dataset
About 141 days separate Timber Lake's last and first frost, putting it 36,962 of 40,283 ZIP codes nationally. Within SD, it ranks 295 of 378.
Learn more
Two guides worth reading on 57656: the frost range, on how to read the range around Timber Lake's dates instead of trusting one, and local microclimates, on what one yard in Timber Lake can differ from the 57656 normal.