Denver, CO 80022 Frost Dates
When can you plant in Denver, CO?
The last spring frost here typically falls around 05/04, about 249 days from today. The first fall frost typically arrives around 10/08, about 156 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 Denver, not a forecast for this year.
What to do before the first frost
About 6 weeks of growing season left in Denver before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 05/04 isn't a guarantee
05/04 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. 05/16 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Denver compares
At roughly 156 frost-free days, Denver places 33,477 of 40,283 ZIP codes in this dataset. Within CO, it ranks 185 of 624.
Learn more
zone vs. frost date covers why Zone 6a and Denver's frost date answer different questions. the frost range covers how to read the range around Denver's dates instead of trusting one.