Whitten, IA 50269 Frost Dates
Whitten, IA: when does the frost end?
Around 04/27 is the usual last spring frost, about 242 days away. Fall's first freeze usually shows up around 10/10, roughly 165 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Whitten in Zone 5a (-20 to -15°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 Whitten'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
04/27 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/13 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/08 and only about 1 year in 10 sees frost after that.
Whitten against the rest of the dataset
Whitten's growing season runs about 165 days, ranking 30,783 of 40,283 US ZIP codes measured here, longest to shortest. Within IA, it ranks 566 of 1,042.
Learn more
Before leaning on 50269's figures: local microclimates explains what one yard in Whitten can differ from the 50269 normal, while zone vs. frost date explains why Zone 5a and Whitten's frost date answer different questions.