Reliance, SD 57339 Frost Dates
Reliance, SD: when does the frost end?
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.
The USDA Plant Hardiness Zone Map puts Reliance in Zone 4b (-25 to -20°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
Stretching the season past the first frost
With roughly 5 weeks until Reliance's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
How much risk comes with planting early here
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
About 140 days separate Reliance's last and first frost, putting it 37,190 of 40,283 ZIP codes nationally. Within SD, it ranks 311 of 378.
Learn more
Before leaning on 57339's figures: the frost range explains how to read the range around Reliance's dates instead of trusting one, while local microclimates explains what one yard in Reliance can differ from the 57339 normal.