Swaledale, IA 50477 Frost Dates
50477, near Swaledale, IA: the frost window
Around 05/03 is the usual last spring frost, about 248 days away. Fall's first freeze usually shows up around 10/01, roughly 150 days after the last spring frost.
Swaledale 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
Swaledale's growing season runs out in roughly 5 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
05/03 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/19 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/15 and only about 1 year in 10 sees frost after that.
Swaledale against the rest of the dataset
About 150 days separate Swaledale's last and first frost, putting it 35,449 of 40,283 ZIP codes nationally. Within IA, it ranks 1,025 of 1,042.
Learn more
Two guides worth reading on 50477: zone vs. frost date, on why Zone 5a and Swaledale's frost date answer different questions, and the frost range, on how to read the range around Swaledale's dates instead of trusting one.