San Luis, CO 81152 Frost Dates
San Luis, CO: when does the frost end?
The last spring frost here typically falls around 05/28, about 273 days from today. Fall's first freeze usually shows up around 09/21, roughly 115 days after the last spring frost.
San Luis 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
With roughly 3 weeks until San Luis's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 05/28 isn't a guarantee
05/28 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/13 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/11 and only about 1 year in 10 sees frost after that.
San Luis against the rest of the dataset
San Luis's growing season runs about 115 days, ranking 39,331 of 40,283 US ZIP codes measured here, longest to shortest. Within CO, it ranks 485 of 624.
Learn more
Before leaning on 81152's figures: zone vs. frost date explains why Zone 5b and San Luis's frost date answer different questions, while the frost range explains how to read the range around San Luis's dates instead of trusting one.