Twentynine Palms, CA 92340 Frost Dates
92340, near Twentynine Palms, CA: the frost window
The last spring frost here typically falls around 03/06, about 190 days from today. Fall's first freeze usually shows up around 12/08, roughly 272 days after the last spring frost.
Zone 8b (15 to 20°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.
Why 03/06 isn't a guarantee
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
About 272 days separate Twentynine Palms's last and first frost, putting it 5,340 of 40,283 ZIP codes nationally. Within CA, it ranks 1,845 of 2,555.
Learn more
Two guides worth reading on 92340: the frost range, on how to read the range around Twentynine Palms's dates instead of trusting one, and local microclimates, on what one yard in Twentynine Palms can differ from the 92340 normal.