Letts, IA 52754 Frost Dates
Letts, IA: when does the frost end?
Typically, the last spring freeze lands around 04/26, roughly 241 days out. Fall's first freeze usually shows up around 10/10, roughly 167 days after the last spring frost.
Letts 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 6 weeks until Letts's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Letts's last frost
04/26 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/11 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.
Letts against the rest of the dataset
At roughly 167 frost-free days, Letts places 30,170 of 40,283 ZIP codes in this dataset. Within IA, it ranks 429 of 1,042.
Learn more
Before leaning on 52754's figures: local microclimates explains what one yard in Letts can differ from the 52754 normal, while zone vs. frost date explains why Zone 5b and Letts's frost date answer different questions.