El Cajon, CA 91906 Frost Dates
When can you plant in El Cajon, CA?
Around 04/30 is the usual last spring frost, about 245 days away. The first fall frost typically arrives around 10/26, about 174 frost-free days later.
The USDA Plant Hardiness Zone Map puts El Cajon in Zone 9a (20 to 25°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
What to do before the first frost
About 8 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.
The actual range around El Cajon's last frost
04/30 is the middle of 30 years of NOAA records, not a promise. Plant by 04/09 and you're betting against frost in roughly 9 years out of 10. 06/01 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 174 days, ranking 27,320 of 40,283 US ZIP codes measured here, longest to shortest. Within CA, it ranks 2,362 of 2,555.
Learn more
local microclimates covers what one yard in El Cajon can differ from the 91906 normal. zone vs. frost date covers why Zone 9a and El Cajon's frost date answer different questions.