Tropic, UT 84776 Frost Dates
When can you plant in Tropic, UT?
Typically, the last spring freeze lands around 05/23, roughly 268 days out. The first fall frost typically arrives around 09/27, about 125 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 Tropic, not a forecast for this year.
What to do before the first frost
About 4 weeks of growing season left in Tropic before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 05/23 isn't a guarantee
05/23 is the middle of 30 years of NOAA records, not a promise. Plant by 05/08 and you're betting against frost in roughly 9 years out of 10. 06/09 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Tropic compares
Tropic's growing season runs about 125 days, ranking 38,790 of 40,283 US ZIP codes measured here, longest to shortest. Within UT, it ranks 267 of 344.
Learn more
local microclimates covers what one yard in Tropic can differ from the 84776 normal. zone vs. frost date covers why Zone 6a and Tropic's frost date answer different questions.