Thayer, IA 50254 Frost Dates
Thayer, IA: when does the frost end?
The last spring frost here typically falls around 04/23, about 238 days from today. Fall's first freeze usually shows up around 10/17, roughly 176 days after the last spring frost.
Thayer sits in USDA Zone 5b (-15 to -10°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 7 weeks until Thayer'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
04/23 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/07 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.
Thayer against the rest of the dataset
At roughly 176 frost-free days, Thayer places 26,684 of 40,283 ZIP codes in this dataset. Within IA, it ranks 167 of 1,042.
Learn more
Before leaning on 50254's figures: zone vs. frost date explains why Zone 5b and Thayer's frost date answer different questions, while the frost range explains how to read the range around Thayer's dates instead of trusting one.