Summit, SD 57266 Frost Dates
Frost dates for Summit, SD, ZIP 57266
Around 05/14 is the usual last spring frost, about 259 days away. The first fall frost typically arrives around 09/28, about 136 frost-free days later.
The USDA Plant Hardiness Zone Map puts Summit in Zone 4a (-30 to -25°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
What to do before the first frost
Zone 4a around Summit has about 4 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.
How much risk comes with planting early here
05/14 is the middle of 30 years of NOAA records, not a promise. Plant by 05/01 and you're betting against frost in roughly 9 years out of 10. 05/28 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Summit compares
At roughly 136 frost-free days, Summit places 37,791 of 40,283 ZIP codes in this dataset. Within SD, it ranks 350 of 378.
Learn more
the frost range explains how to read the range around Summit's dates instead of trusting one, and local microclimates explains what one yard in Summit can differ from the 57266 normal.