Green Mountain Falls, CO 80819 Frost Dates
When can you plant in Green Mountain Falls, CO?
Typically, the last spring freeze lands around 06/03, roughly 279 days out. The first fall frost typically arrives around 09/17, about 102 frost-free days later.
Green Mountain Falls 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.
What to do before the first frost
About 3 weeks of growing season left in Green Mountain Falls before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 06/03 isn't a guarantee
06/03 is the middle of 30 years of NOAA records, not a promise. Plant by 05/21 and you're betting against frost in roughly 9 years out of 10. 06/23 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Green Mountain Falls compares
Green Mountain Falls's growing season runs about 102 days, ranking 39,668 of 40,283 US ZIP codes measured here, longest to shortest. Within CO, it ranks 527 of 624.
Learn more
local microclimates covers what one yard in Green Mountain Falls can differ from the 80819 normal. zone vs. frost date covers why Zone 5b and Green Mountain Falls's frost date answer different questions.