Prairie City, OR 97869 Frost Dates
Frost dates for Prairie City, OR, ZIP 97869
Around 05/28 is the usual last spring frost, about 273 days away. The first fall frost typically arrives around 09/18, about 113 frost-free days later.
The USDA Plant Hardiness Zone Map puts Prairie City in Zone 6b (-5 to 0°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
Zone 6b around Prairie City has about 3 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 05/28 isn't a guarantee
05/28 is the middle of 30 years of NOAA records, not a promise. Plant by 05/12 and you're betting against frost in roughly 9 years out of 10. 06/15 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Prairie City compares
At roughly 113 frost-free days, Prairie City places 39,401 of 40,283 ZIP codes in this dataset. Within OR, it ranks 396 of 463.
Learn more
zone vs. frost date explains why Zone 6b and Prairie City's frost date answer different questions, and the frost range explains how to read the range around Prairie City's dates instead of trusting one.