Twentynine Palms, CA 91785 Frost Dates
91785, near Twentynine Palms, CA: the frost window
Around 03/06 is the usual last spring frost, about 190 days away. Fall's first freeze usually shows up around 12/08, roughly 272 days after the last spring frost.
Zone 10a (30 to 35°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 Twentynine Palms, not a forecast for this year.
Stretching the season past the first frost
Twentynine Palms'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.
How much risk comes with planting early here
03/06 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 01/17 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/09 and only about 1 year in 10 sees frost after that.
Twentynine Palms against the rest of the dataset
Twentynine Palms's growing season runs about 272 days, ranking 5,335 of 40,283 US ZIP codes measured here, longest to shortest. Within CA, it ranks 1,840 of 2,555.
Learn more
Two guides worth reading on 91785: zone vs. frost date, on why Zone 10a and Twentynine Palms's frost date answer different questions, and the frost range, on how to read the range around Twentynine Palms's dates instead of trusting one.