Littleton, CO 80122 Frost Dates
Frost dates for Littleton, CO, ZIP 80122
The last spring frost here typically falls around 05/05, about 250 days from today. The first fall frost typically arrives around 10/08, about 154 frost-free days later.
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 Littleton, not a forecast for this year.
What to do before the first frost
Zone 6a around Littleton has about 6 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 05/05 isn't a guarantee
05/05 is the middle of 30 years of NOAA records, not a promise. Plant by 04/24 and you're betting against frost in roughly 9 years out of 10. 05/17 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Littleton compares
About 154 days separate Littleton's last and first frost, putting it 34,205 of 40,283 ZIP codes nationally. Within CO, it ranks 260 of 624.
Learn more
the frost range explains how to read the range around Littleton's dates instead of trusting one, and local microclimates explains what one yard in Littleton can differ from the 80122 normal.