Fillmore, UT 84631 Frost Dates
84631, near Fillmore, UT: the frost window
The last spring frost here typically falls around 05/21, about 266 days from today. Fall's first freeze usually shows up around 09/24, roughly 125 days after the last spring frost.
Fillmore 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
Fillmore's growing season runs out in roughly 4 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 Fillmore's last frost
05/21 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/04 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/07 and only about 1 year in 10 sees frost after that.
Fillmore against the rest of the dataset
About 125 days separate Fillmore's last and first frost, putting it 38,761 of 40,283 ZIP codes nationally. Within UT, it ranks 260 of 344.
Learn more
Two guides worth reading on 84631: the frost range, on how to read the range around Fillmore's dates instead of trusting one, and local microclimates, on what one yard in Fillmore can differ from the 84631 normal.