Idaho Springs, CO 80452 Frost Dates
Idaho Springs, CO: when does the frost end?
Around 05/30 is the usual last spring frost, about 275 days away. Fall's first freeze usually shows up around 09/19, roughly 112 days after the last spring frost.
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 Idaho Springs, not a forecast for this year.
Stretching the season past the first frost
With roughly 3 weeks until Idaho Springs's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Idaho Springs's last frost
05/30 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/17 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/14 and only about 1 year in 10 sees frost after that.
Idaho Springs against the rest of the dataset
At roughly 112 frost-free days, Idaho Springs places 39,422 of 40,283 ZIP codes in this dataset. Within CO, it ranks 498 of 624.
Learn more
Before leaning on 80452's figures: local microclimates explains what one yard in Idaho Springs can differ from the 80452 normal, while zone vs. frost date explains why Zone 5b and Idaho Springs's frost date answer different questions.