Sioux City, IA 51106 Frost Dates
Sioux City, IA: when does the frost end?
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.
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
With roughly 5 weeks until Sioux City's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
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.
Sioux City against the rest of the dataset
About 159 days separate Sioux City's last and first frost, putting it 32,576 of 40,283 ZIP codes nationally. Within IA, it ranks 774 of 1,042.
Learn more
Before leaning on 51106's figures: the frost range explains how to read the range around Sioux City's dates instead of trusting one, while local microclimates explains what one yard in Sioux City can differ from the 51106 normal.