La Porte City, IA 50651 Frost Dates
50651, near La Porte City, IA: the frost window
The last spring frost here typically falls around 04/27, about 242 days from today. Fall's first freeze usually shows up around 10/10, roughly 165 days after the last spring frost.
La Porte City 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
La Porte City's growing season runs out in roughly 6 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 04/27 isn't a guarantee
04/27 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 05/10 and only about 1 year in 10 sees frost after that.
La Porte City against the rest of the dataset
About 165 days separate La Porte City's last and first frost, putting it 30,599 of 40,283 ZIP codes nationally. Within IA, it ranks 503 of 1,042.
Learn more
Two guides worth reading on 50651: zone vs. frost date, on why Zone 5a and La Porte City's frost date answer different questions, and the frost range, on how to read the range around La Porte City's dates instead of trusting one.