Eureka, UT 84628 Frost Dates
Frost dates for Eureka, UT, ZIP 84628
Around 05/15 is the usual last spring frost, about 260 days away. The first fall frost typically arrives around 10/01, about 137 frost-free days later.
Zone 6b (-5 to 0°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 Eureka, not a forecast for this year.
What to do before the first frost
Zone 6b around Eureka has about 5 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 05/15 isn't a guarantee
05/15 is the middle of 30 years of NOAA records, not a promise. Plant by 04/30 and you're betting against frost in roughly 9 years out of 10. 06/05 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Eureka compares
Eureka's growing season runs about 137 days, ranking 37,557 of 40,283 US ZIP codes measured here, longest to shortest. Within UT, it ranks 228 of 344.
Learn more
the frost range explains how to read the range around Eureka's dates instead of trusting one, and local microclimates explains what one yard in Eureka can differ from the 84628 normal.