Winfield, IA 52659 Frost Dates
Winfield, IA: when does the frost end?
Typically, the last spring freeze lands around 04/26, roughly 241 days out. Fall's first freeze usually shows up around 10/10, roughly 167 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Winfield in Zone 5b (-15 to -10°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
Stretching the season past the first frost
With roughly 6 weeks until Winfield's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 04/26 isn't a guarantee
04/26 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/11 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.
Winfield against the rest of the dataset
Winfield's growing season runs about 167 days, ranking 30,083 of 40,283 US ZIP codes measured here, longest to shortest. Within IA, it ranks 420 of 1,042.
Learn more
Before leaning on 52659's figures: local microclimates explains what one yard in Winfield can differ from the 52659 normal, while zone vs. frost date explains why Zone 5b and Winfield's frost date answer different questions.