Humboldt, IA 50548 Frost Dates
50548, near Humboldt, IA: the frost window
The last spring frost here typically falls around 04/26, about 241 days from today. Fall's first freeze usually shows up around 10/12, roughly 169 days after the last spring frost.
Humboldt 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
Humboldt'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.
How much risk comes with planting early here
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 05/07 and only about 1 year in 10 sees frost after that.
Humboldt against the rest of the dataset
About 169 days separate Humboldt's last and first frost, putting it 29,416 of 40,283 ZIP codes nationally. Within IA, it ranks 332 of 1,042.
Learn more
Two guides worth reading on 50548: local microclimates, on what one yard in Humboldt can differ from the 50548 normal, and zone vs. frost date, on why Zone 5a and Humboldt's frost date answer different questions.