Mayfield, UT 84665 Frost Dates
84665, near Mayfield, UT: the frost window
The last spring frost here typically falls around 05/11, about 256 days from today. Fall's first freeze usually shows up around 10/06, roughly 146 days after the last spring frost.
Zone 6a (-10 to -5°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 Mayfield, not a forecast for this year.
Stretching the season past the first frost
Mayfield'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.
Why 05/11 isn't a guarantee
05/11 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/25 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/01 and only about 1 year in 10 sees frost after that.
Mayfield against the rest of the dataset
At roughly 146 frost-free days, Mayfield places 36,085 of 40,283 ZIP codes in this dataset. Within UT, it ranks 208 of 344.
Learn more
Two guides worth reading on 84665: zone vs. frost date, on why Zone 6a and Mayfield's frost date answer different questions, and the frost range, on how to read the range around Mayfield's dates instead of trusting one.