Rancho Cucamonga, CA 91701 Frost Dates
Frost dates for Rancho Cucamonga, CA, ZIP 91701
Around 01/04 is the usual last spring frost, about 129 days away. The first fall frost typically arrives around 12/30, about 365 frost-free days later.
Rancho Cucamonga sits in USDA Zone 10a (30 to 35°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 10a around Rancho Cucamonga has about 18 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
01/04 is the middle of 30 years of NOAA records, not a promise. Plant by 02/07 and you're betting against frost in roughly 9 years out of 10. 12/14 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Rancho Cucamonga compares
About 365 days separate Rancho Cucamonga's last and first frost, putting it 376 of 40,283 ZIP codes nationally. Within CA, it ranks 130 of 2,555.
Learn more
zone vs. frost date explains why Zone 10a and Rancho Cucamonga's frost date answer different questions, and the frost range explains how to read the range around Rancho Cucamonga's dates instead of trusting one.