Wiley, CO 81057 Frost Dates
81057, near Wiley, CO: the frost window
Typically, the last spring freeze lands around 04/24, roughly 239 days out. Fall's first freeze usually shows up around 10/15, roughly 172 days after the last spring frost.
Zone 6a (-10 to -5°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Wiley, not a forecast for this year.
Stretching the season past the first frost
Wiley's growing season runs out in roughly 7 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
04/24 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/09 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/08 and only about 1 year in 10 sees frost after that.
Wiley against the rest of the dataset
At roughly 172 frost-free days, Wiley places 28,459 of 40,283 ZIP codes in this dataset. Within CO, it ranks 17 of 624.
Learn more
Two guides worth reading on 81057: zone vs. frost date, on why Zone 6a and Wiley's frost date answer different questions, and the frost range, on how to read the range around Wiley's dates instead of trusting one.