Larkspur, CO 80118 Frost Dates
Frost dates for Larkspur, CO, ZIP 80118
Around 05/14 is the usual last spring frost, about 259 days away. The first fall frost typically arrives around 10/01, about 138 frost-free days later.
Zone 5b (-15 to -10°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 Larkspur, not a forecast for this year.
What to do before the first frost
Zone 5b around Larkspur 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.
Why 05/14 isn't a guarantee
05/14 is the middle of 30 years of NOAA records, not a promise. Plant by 05/02 and you're betting against frost in roughly 9 years out of 10. 05/31 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Larkspur compares
At roughly 138 frost-free days, Larkspur places 37,457 of 40,283 ZIP codes in this dataset. Within CO, it ranks 411 of 624.
Learn more
the frost range explains how to read the range around Larkspur's dates instead of trusting one, and local microclimates explains what one yard in Larkspur can differ from the 80118 normal.