Pasadena, CA 91101 Frost Dates
Pasadena, CA: when does the frost end?
Typically, the last spring freeze lands around 01/08, roughly 133 days out. Fall's first freeze usually shows up around 01/07, roughly 365 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 Pasadena, not a forecast for this year.
Stretching the season past the first frost
With roughly 19 weeks until Pasadena's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
How much risk comes with planting early here
01/08 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 02/17 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 12/20 and only about 1 year in 10 sees frost after that.
Pasadena against the rest of the dataset
Pasadena's growing season runs about 365 days, ranking 419 of 40,283 US ZIP codes measured here, longest to shortest. Within CA, it ranks 162 of 2,555.
Learn more
Before leaning on 91101's figures: local microclimates explains what one yard in Pasadena can differ from the 91101 normal, while zone vs. frost date explains why Zone 10a and Pasadena's frost date answer different questions.