Holstein, IA 51025 Frost Dates
Holstein, IA: when does the frost end?
Typically, the last spring freeze lands around 04/30, roughly 245 days out. Fall's first freeze usually shows up around 10/09, roughly 162 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 Holstein, not a forecast for this year.
Stretching the season past the first frost
With roughly 6 weeks until Holstein'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
04/30 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/15 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/11 and only about 1 year in 10 sees frost after that.
Holstein against the rest of the dataset
About 162 days separate Holstein's last and first frost, putting it 31,777 of 40,283 ZIP codes nationally. Within IA, it ranks 704 of 1,042.
Learn more
Before leaning on 51025's figures: local microclimates explains what one yard in Holstein can differ from the 51025 normal, while zone vs. frost date explains why Zone 5a and Holstein's frost date answer different questions.