Monument, CO 80921 Frost Dates
80921, near Monument, CO: the frost window
The last spring frost here typically falls around 05/14, about 259 days from today. Fall's first freeze usually shows up around 10/01, roughly 138 days after the last spring frost.
Monument sits in USDA Zone 5b (-15 to -10°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
Stretching the season past the first frost
Monument's growing season runs out in roughly 5 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 05/14 isn't a guarantee
05/14 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/02 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/31 and only about 1 year in 10 sees frost after that.
Monument against the rest of the dataset
Monument's growing season runs about 138 days, ranking 37,362 of 40,283 US ZIP codes measured here, longest to shortest. Within CO, it ranks 409 of 624.
Learn more
Two guides worth reading on 80921: local microclimates, on what one yard in Monument can differ from the 80921 normal, and zone vs. frost date, on why Zone 5b and Monument's frost date answer different questions.