Sibley, IA 51249 Frost Dates
Sibley, IA: when does the frost end?
The last spring frost here typically falls around 05/05, about 250 days from today. Fall's first freeze usually shows up around 10/03, roughly 152 days after the last spring frost.
Sibley sits in USDA Zone 4b (-25 to -20°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 Sibley's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
How much risk comes with planting early here
05/05 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/22 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/17 and only about 1 year in 10 sees frost after that.
Sibley against the rest of the dataset
About 152 days separate Sibley's last and first frost, putting it 34,763 of 40,283 ZIP codes nationally. Within IA, it ranks 946 of 1,042.
Learn more
Before leaning on 51249's figures: the frost range explains how to read the range around Sibley's dates instead of trusting one, while local microclimates explains what one yard in Sibley can differ from the 51249 normal.