Denver, CO 80045 Frost Dates
Denver, CO: when does the frost end?
Typically, the last spring freeze lands around 05/04, roughly 249 days out. Fall's first freeze usually shows up around 10/08, roughly 156 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Denver in Zone 6a (-10 to -5°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
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
About 156 days separate Denver's last and first frost, putting it 33,478 of 40,283 ZIP codes nationally. Within CO, it ranks 186 of 624.
Learn more
Before leaning on 80045'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 80045 normal.