Lyons, CO 80540 Frost Dates
When can you plant in Lyons, CO?
The last spring frost here typically falls around 06/14, about 290 days from today. The first fall frost typically arrives around 09/12, about 92 frost-free days later.
Lyons sits in USDA Zone 5b (-15 to -10°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
About 2 weeks of growing season left in Lyons before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 06/14 isn't a guarantee
06/14 is the middle of 30 years of NOAA records, not a promise. Plant by 05/24 and you're betting against frost in roughly 9 years out of 10. 06/28 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Lyons compares
Lyons's growing season runs about 92 days, ranking 39,884 of 40,283 US ZIP codes measured here, longest to shortest. Within CO, it ranks 543 of 624.
Learn more
the frost range covers how to read the range around Lyons's dates instead of trusting one. local microclimates covers what one yard in Lyons can differ from the 80540 normal.