El Cajon, CA 92020 Frost Dates
When can you plant in El Cajon, CA?
Around 01/06 is the usual last spring frost, about 131 days away. The first fall frost typically arrives around 12/21, about 350 frost-free days later.
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 El Cajon, not a forecast for this year.
What to do before the first frost
About 16 weeks of growing season left in El Cajon before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 01/06 isn't a guarantee
01/06 is the middle of 30 years of NOAA records, not a promise. Plant by 02/07 and you're betting against frost in roughly 9 years out of 10. 12/13 is the safer bet, historically only a 1-in-10 chance of frost that late.
How El Cajon compares
El Cajon's growing season runs about 350 days, ranking 2,319 of 40,283 US ZIP codes measured here, longest to shortest. Within CA, it ranks 1,025 of 2,555.
Learn more
zone vs. frost date covers why Zone 10a and El Cajon's frost date answer different questions. the frost range covers how to read the range around El Cajon's dates instead of trusting one.