Washington, UT 84780 Frost Dates
When can you plant in Washington, UT?
Around 03/14 is the usual last spring frost, about 198 days away. The first fall frost typically arrives around 11/10, about 239 frost-free days later.
The USDA Plant Hardiness Zone Map puts Washington in Zone 8b (15 to 20°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
What to do before the first frost
About 11 weeks of growing season left in Washington before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
The actual range around Washington's last frost
03/14 is the middle of 30 years of NOAA records, not a promise. Plant by 02/27 and you're betting against frost in roughly 9 years out of 10. 04/06 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Washington compares
Washington's growing season runs about 239 days, ranking 8,780 of 40,283 US ZIP codes measured here, longest to shortest. Within UT, it ranks 4 of 344.
Learn more
zone vs. frost date covers why Zone 8b and Washington's frost date answer different questions. the frost range covers how to read the range around Washington's dates instead of trusting one.