Windsor, CO 80551 Frost Dates
80551, near Windsor, CO: the frost window
Typically, the last spring freeze lands around 05/03, roughly 248 days out. Fall's first freeze usually shows up around 10/06, roughly 154 days after the last spring frost.
Windsor 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
Windsor's growing season runs out in roughly 6 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
The actual range around Windsor's last frost
05/03 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/21 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/15 and only about 1 year in 10 sees frost after that.
Windsor against the rest of the dataset
About 154 days separate Windsor's last and first frost, putting it 34,208 of 40,283 ZIP codes nationally. Within CO, it ranks 263 of 624.
Learn more
Two guides worth reading on 80551: zone vs. frost date, on why Zone 5b and Windsor's frost date answer different questions, and the frost range, on how to read the range around Windsor's dates instead of trusting one.