Williams, AZ 86320 Frost Dates
Frost dates for Williams, AZ, ZIP 86320
The last spring frost here typically falls around 05/10, about 255 days from today. The first fall frost typically arrives around 10/15, about 154 frost-free days later.
Williams sits in USDA Zone 7a (0 to 5°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 7a around Williams has about 7 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.
How much risk comes with planting early here
05/10 is the middle of 30 years of NOAA records, not a promise. Plant by 04/26 and you're betting against frost in roughly 9 years out of 10. 05/29 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Williams compares
Williams's growing season runs about 154 days, ranking 34,286 of 40,283 US ZIP codes measured here, longest to shortest. Within AZ, it ranks 458 of 506.
Learn more
local microclimates explains what one yard in Williams can differ from the 86320 normal, and zone vs. frost date explains why Zone 7a and Williams's frost date answer different questions.