Rancho Cucamonga, CA 92397 Frost Dates
Frost dates for Rancho Cucamonga, CA, ZIP 92397
The last spring frost here typically falls around 05/16, about 261 days from today. The first fall frost typically arrives around 10/13, about 151 frost-free days later.
Zone 7b (5 to 10°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Rancho Cucamonga, not a forecast for this year.
What to do before the first frost
Zone 7b around Rancho Cucamonga 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.
The actual range around Rancho Cucamonga's last frost
05/16 is the middle of 30 years of NOAA records, not a promise. Plant by 04/25 and you're betting against frost in roughly 9 years out of 10. 06/09 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Rancho Cucamonga compares
Rancho Cucamonga's growing season runs about 151 days, ranking 34,928 of 40,283 US ZIP codes measured here, longest to shortest. Within CA, it ranks 2,429 of 2,555.
Learn more
the frost range explains how to read the range around Rancho Cucamonga's dates instead of trusting one, and local microclimates explains what one yard in Rancho Cucamonga can differ from the 92397 normal.