Littleton, CO 80126 Frost Dates
Frost dates for Littleton, CO, ZIP 80126
Typically, the last spring freeze lands around 05/05, roughly 250 days out. The first fall frost typically arrives around 10/08, about 154 frost-free days later.
The USDA Plant Hardiness Zone Map puts Littleton in Zone 6a (-10 to -5°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
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.
How much risk comes with planting early here
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
Littleton's growing season runs about 154 days, ranking 34,206 of 40,283 US ZIP codes measured here, longest to shortest. Within CO, it ranks 261 of 624.
Learn more
zone vs. frost date explains why Zone 6a and Littleton's frost date answer different questions, and the frost range explains how to read the range around Littleton's dates instead of trusting one.