Houghton, IA 52631 Frost Dates
Houghton, IA: when does the frost end?
Typically, the last spring freeze lands around 04/17, roughly 232 days out. Fall's first freeze usually shows up around 10/22, roughly 187 days after the last spring frost.
Houghton sits in USDA Zone 6a (-10 to -5°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 8 weeks until Houghton's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 04/17 isn't a guarantee
04/17 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/04 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.
Houghton against the rest of the dataset
About 187 days separate Houghton's last and first frost, putting it 22,627 of 40,283 ZIP codes nationally. Within IA, it ranks 24 of 1,042.
Learn more
Before leaning on 52631's figures: local microclimates explains what one yard in Houghton can differ from the 52631 normal, while zone vs. frost date explains why Zone 6a and Houghton's frost date answer different questions.