Denver, CO 80207 Frost Dates
Denver, CO: when does the frost end?
The last spring frost here typically falls around 05/04, about 249 days from today. Fall's first freeze usually shows up around 10/08, roughly 156 days after the last spring frost.
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.
Stretching the season past the first frost
With roughly 6 weeks until Denver's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 05/04 isn't a guarantee
05/04 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/20 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/16 and only about 1 year in 10 sees frost after that.
Denver against the rest of the dataset
Denver's growing season runs about 156 days, ranking 33,480 of 40,283 US ZIP codes measured here, longest to shortest. Within CO, it ranks 188 of 624.
Learn more
Before leaning on 80207's figures: the frost range explains how to read the range around Denver's dates instead of trusting one, while local microclimates explains what one yard in Denver can differ from the 80207 normal.