Iowa City, IA 52242 Frost Dates
Iowa City, IA: when does the frost end?
The last spring frost here typically falls around 04/21, about 236 days from today. Fall's first freeze usually shows up around 10/18, roughly 180 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Iowa City 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 7 weeks until Iowa City's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Iowa City's last frost
04/21 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/05 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/06 and only about 1 year in 10 sees frost after that.
Iowa City against the rest of the dataset
About 180 days separate Iowa City's last and first frost, putting it 24,763 of 40,283 ZIP codes nationally. Within IA, it ranks 87 of 1,042.
Learn more
Before leaning on 52242's figures: zone vs. frost date explains why Zone 5b and Iowa City's frost date answer different questions, while the frost range explains how to read the range around Iowa City's dates instead of trusting one.