River Heights, UT 84321 Frost Dates
Frost dates for River Heights, UT, ZIP 84321
Around 04/30 is the usual last spring frost, about 245 days away. The first fall frost typically arrives around 10/16, about 166 frost-free days later.
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 River Heights, not a forecast for this year.
What to do before the first frost
Zone 6a around River Heights has about 7 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.
Why 04/30 isn't a guarantee
04/30 is the middle of 30 years of NOAA records, not a promise. Plant by 04/14 and you're betting against frost in roughly 9 years out of 10. 05/19 is the safer bet, historically only a 1-in-10 chance of frost that late.
How River Heights compares
About 166 days separate River Heights's last and first frost, putting it 30,386 of 40,283 ZIP codes nationally. Within UT, it ranks 140 of 344.
Learn more
the frost range explains how to read the range around River Heights's dates instead of trusting one, and local microclimates explains what one yard in River Heights can differ from the 84321 normal.