Lyons, CO 80533 Frost Dates
Frost dates for Lyons, CO, ZIP 80533
Typically, the last spring freeze lands around 05/06, roughly 251 days out. The first fall frost typically arrives around 10/05, about 151 frost-free days later.
Lyons sits in USDA Zone 6a (-10 to -5°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.
What to do before the first frost
Zone 6a around Lyons 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.
The actual range around Lyons's last frost
05/06 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. 05/18 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Lyons compares
At roughly 151 frost-free days, Lyons places 35,056 of 40,283 ZIP codes in this dataset. Within CO, it ranks 315 of 624.
Learn more
local microclimates explains what one yard in Lyons can differ from the 80533 normal, and zone vs. frost date explains why Zone 6a and Lyons's frost date answer different questions.