Hartford, SD 57033 Frost Dates
Hartford, SD: when does the frost end?
Typically, the last spring freeze lands around 05/01, roughly 246 days out. Fall's first freeze usually shows up around 10/06, roughly 157 days after the last spring frost.
Zone 5a (-20 to -15°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 Hartford, not a forecast for this year.
Stretching the season past the first frost
With roughly 6 weeks until Hartford's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Hartford's last frost
05/01 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/18 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/14 and only about 1 year in 10 sees frost after that.
Hartford against the rest of the dataset
About 157 days separate Hartford's last and first frost, putting it 33,314 of 40,283 ZIP codes nationally. Within SD, it ranks 68 of 378.
Learn more
Before leaning on 57033's figures: local microclimates explains what one yard in Hartford can differ from the 57033 normal, while zone vs. frost date explains why Zone 5a and Hartford's frost date answer different questions.