South Sioux City, NE 68776 Frost Dates
68776, near South Sioux City, NE: the frost window
Typically, the last spring freeze lands around 04/29, roughly 244 days out. Fall's first freeze usually shows up around 10/05, roughly 159 days after the last spring frost.
South Sioux City sits in USDA Zone 5a (-20 to -15°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
South Sioux City'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 04/29 isn't a guarantee
04/29 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/16 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.
South Sioux City against the rest of the dataset
About 159 days separate South Sioux City's last and first frost, putting it 32,614 of 40,283 ZIP codes nationally. Within NE, it ranks 401 of 605.
Learn more
Two guides worth reading on 68776: local microclimates, on what one yard in South Sioux City can differ from the 68776 normal, and zone vs. frost date, on why Zone 5a and South Sioux City's frost date answer different questions.