Coulter, IA 50431 Frost Dates
Coulter, IA: when does the frost end?
Typically, the last spring freeze lands around 04/28, roughly 243 days out. Fall's first freeze usually shows up around 10/10, roughly 164 days after the last spring frost.
Coulter sits in USDA Zone 5a (-20 to -15°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
Stretching the season past the first frost
With roughly 6 weeks until Coulter's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Coulter's last frost
04/28 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 05/11 and only about 1 year in 10 sees frost after that.
Coulter against the rest of the dataset
About 164 days separate Coulter's last and first frost, putting it 31,208 of 40,283 ZIP codes nationally. Within IA, it ranks 633 of 1,042.
Learn more
Before leaning on 50431's figures: zone vs. frost date explains why Zone 5a and Coulter's frost date answer different questions, while the frost range explains how to read the range around Coulter's dates instead of trusting one.