Renton, WA 98058 Frost Dates
Frost dates for Renton, WA, ZIP 98058
Around 03/20 is the usual last spring frost, about 204 days away. The first fall frost typically arrives around 11/10, about 233 frost-free days later.
Renton sits in USDA Zone 8b (15 to 20°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
What to do before the first frost
Zone 8b around Renton has about 11 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.
The actual range around Renton's last frost
03/20 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. 04/08 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Renton compares
At roughly 233 frost-free days, Renton places 9,844 of 40,283 ZIP codes in this dataset. Within WA, it ranks 175 of 700.
Learn more
local microclimates explains what one yard in Renton can differ from the 98058 normal, and zone vs. frost date explains why Zone 8b and Renton's frost date answer different questions.