Nunn, CO 80648 Frost Dates
80648, near Nunn, CO: the frost window
The last spring frost here typically falls around 05/13, about 258 days from today. Fall's first freeze usually shows up around 09/27, roughly 136 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Nunn in Zone 5a (-20 to -15°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
Stretching the season past the first frost
Nunn's growing season runs out in roughly 4 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
05/13 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/02 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/27 and only about 1 year in 10 sees frost after that.
Nunn against the rest of the dataset
Nunn's growing season runs about 136 days, ranking 37,761 of 40,283 US ZIP codes measured here, longest to shortest. Within CO, it ranks 421 of 624.
Learn more
Two guides worth reading on 80648: local microclimates, on what one yard in Nunn can differ from the 80648 normal, and zone vs. frost date, on why Zone 5a and Nunn's frost date answer different questions.