Northville, SD 57465 Frost Dates
Northville, SD: when does the frost end?
Typically, the last spring freeze lands around 05/11, roughly 256 days out. Fall's first freeze usually shows up around 09/27, roughly 137 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Northville in Zone 4a (-30 to -25°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 4 weeks until Northville's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 05/11 isn't a guarantee
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 05/23 and only about 1 year in 10 sees frost after that.
Northville against the rest of the dataset
At roughly 137 frost-free days, Northville places 37,592 of 40,283 ZIP codes in this dataset. Within SD, it ranks 346 of 378.
Learn more
Before leaning on 57465's figures: local microclimates explains what one yard in Northville can differ from the 57465 normal, while zone vs. frost date explains why Zone 4a and Northville's frost date answer different questions.