Littleton, CO 80120 Frost Dates
When can you plant in Littleton, CO?
Around 05/02 is the usual last spring frost, about 247 days away. The first fall frost typically arrives around 10/11, about 160 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
About 6 weeks of growing season left in Littleton before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
How much risk comes with planting early here
05/02 is the middle of 30 years of NOAA records, not a promise. Plant by 04/20 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 160 days, ranking 32,206 of 40,283 US ZIP codes measured here, longest to shortest. Within CO, it ranks 90 of 624.
Learn more
the frost range covers how to read the range around Littleton's dates instead of trusting one. local microclimates covers what one yard in Littleton can differ from the 80120 normal.