Castle Pines, CO 80108 Frost Dates
80108, near Castle Pines, 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 10/02, roughly 143 days after the last spring frost.
Castle Pines 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
Castle Pines'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.
Why 05/09 isn't a guarantee
05/09 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/30 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/24 and only about 1 year in 10 sees frost after that.
Castle Pines against the rest of the dataset
About 143 days separate Castle Pines's last and first frost, putting it 36,499 of 40,283 ZIP codes nationally. Within CO, it ranks 381 of 624.
Learn more
Two guides worth reading on 80108: zone vs. frost date, on why Zone 5b and Castle Pines's frost date answer different questions, and the frost range, on how to read the range around Castle Pines's dates instead of trusting one.