Flagler, CO 80801 Frost Dates
Frost dates for Flagler, CO, ZIP 80801
Typically, the last spring freeze lands around 05/12, roughly 257 days out. The first fall frost typically arrives around 10/04, about 143 frost-free days later.
Zone 5b (-15 to -10°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 Flagler, not a forecast for this year.
What to do before the first frost
Zone 5b around Flagler has about 5 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.
Why 05/12 isn't a guarantee
05/12 is the middle of 30 years of NOAA records, not a promise. Plant by 04/30 and you're betting against frost in roughly 9 years out of 10. 05/26 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Flagler compares
About 143 days separate Flagler's last and first frost, putting it 36,583 of 40,283 ZIP codes nationally. Within CO, it ranks 385 of 624.
Learn more
local microclimates explains what one yard in Flagler can differ from the 80801 normal, and zone vs. frost date explains why Zone 5b and Flagler's frost date answer different questions.