Middletown, IA 52638 Frost Dates
Middletown, IA: when does the frost end?
Around 04/15 is the usual last spring frost, about 230 days away. Fall's first freeze usually shows up around 10/20, roughly 187 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Middletown in Zone 6a (-10 to -5°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 8 weeks until Middletown's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 04/15 isn't a guarantee
04/15 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/02 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/01 and only about 1 year in 10 sees frost after that.
Middletown against the rest of the dataset
At roughly 187 frost-free days, Middletown places 22,584 of 40,283 ZIP codes in this dataset. Within IA, it ranks 21 of 1,042.
Learn more
Before leaning on 52638's figures: local microclimates explains what one yard in Middletown can differ from the 52638 normal, while zone vs. frost date explains why Zone 6a and Middletown's frost date answer different questions.