Twentynine Palms, CA 92278 Frost Dates
92278, near Twentynine Palms, CA: the frost window
Typically, the last spring freeze lands around 02/28, roughly 184 days out. Fall's first freeze usually shows up around 12/01, roughly 273 days after the last spring frost.
Twentynine Palms sits in USDA Zone 9b (25 to 30°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.
Stretching the season past the first frost
Twentynine Palms's growing season runs out in roughly 14 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 02/28 isn't a guarantee
02/28 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 01/21 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 03/28 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 273 days, ranking 5,191 of 40,283 US ZIP codes measured here, longest to shortest. Within CA, it ranks 1,830 of 2,555.
Learn more
Two guides worth reading on 92278: 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 92278 normal.