Dinuba, CA 93666 Frost Dates
93666, near Dinuba, CA: the frost window
The last spring frost here typically falls around 01/23, about 148 days from today. Fall's first freeze usually shows up around 12/13, roughly 328 days after the last spring frost.
Zone 9b (25 to 30°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 Dinuba, not a forecast for this year.
Stretching the season past the first frost
Dinuba's growing season runs out in roughly 15 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 01/23 isn't a guarantee
01/23 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 02/27 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 12/29 and only about 1 year in 10 sees frost after that.
Dinuba against the rest of the dataset
Dinuba's growing season runs about 328 days, ranking 3,183 of 40,283 US ZIP codes measured here, longest to shortest. Within CA, it ranks 1,364 of 2,555.
Learn more
Two guides worth reading on 93666: local microclimates, on what one yard in Dinuba can differ from the 93666 normal, and zone vs. frost date, on why Zone 9b and Dinuba's frost date answer different questions.