Upland, CA 91786 Frost Dates
Upland, CA: when does the frost end?
The last spring frost here typically falls around 01/04, about 129 days from today. Fall's first freeze usually shows up around 12/30, 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 Upland, not a forecast for this year.
Stretching the season past the first frost
With roughly 18 weeks until Upland's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 01/04 isn't a guarantee
01/04 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 02/07 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 12/14 and only about 1 year in 10 sees frost after that.
Upland against the rest of the dataset
Upland's growing season runs about 365 days, ranking 683 of 40,283 US ZIP codes measured here, longest to shortest. Within CA, it ranks 300 of 2,555.
Learn more
Before leaning on 91786's figures: the frost range explains how to read the range around Upland's dates instead of trusting one, while local microclimates explains what one yard in Upland can differ from the 91786 normal.