Calhan, CO 80808 Frost Dates
80808, near Calhan, CO: the frost window
The last spring frost here typically falls around 05/09, about 254 days from today. Fall's first freeze usually shows up around 10/04, roughly 146 days after the last spring frost.
Calhan sits in USDA Zone 5b (-15 to -10°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
Calhan'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.
The actual range around Calhan's last frost
05/09 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/29 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/22 and only about 1 year in 10 sees frost after that.
Calhan against the rest of the dataset
About 146 days separate Calhan's last and first frost, putting it 36,079 of 40,283 ZIP codes nationally. Within CO, it ranks 360 of 624.
Learn more
Two guides worth reading on 80808: local microclimates, on what one yard in Calhan can differ from the 80808 normal, and zone vs. frost date, on why Zone 5b and Calhan's frost date answer different questions.