Mayfield, UT 84643 Frost Dates
84643, near Mayfield, UT: the frost window
Typically, the last spring freeze lands around 05/11, roughly 256 days out. Fall's first freeze usually shows up around 10/06, roughly 146 days after the last spring frost.
Mayfield sits in USDA Zone 6a (-10 to -5°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
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
About 146 days separate Mayfield's last and first frost, putting it 36,084 of 40,283 ZIP codes nationally. Within UT, it ranks 207 of 344.
Learn more
Two guides worth reading on 84643: 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.