Frost Dates for 95330 — Lathrop, California

Half of springs at Stockton Metro Airport, CA see their last 32°F night by February 6; only one in ten is past it by December 31, and one in ten still has one after February 28. Planting tender crops after February 17 leaves a 30% risk of a frost on them, after February 23 20%, and after February 28 10%. The 22 days between the even-odds date and the one-in-ten date is narrower than at 81% of the 220 California stations behind this site's ZIP pages, so a fixed calendar date is a gamble here.

In fall the first 32°F night comes by December 1 in half of years, as early as November 15 one year in ten, and holds off past December 26 one year in ten. A hard freeze of 28°F follows 15 days later, around December 16; in spring the one-in-ten date for 28°F is February 5, 23 days before the 32°F one. The freeze-free season lasts 304 days in a typical year, longer than at 66% of the 219 California stations; it reaches 339 days one year in ten and falls short of 271 one year in ten. On average 19 nights a year drop to 32°F or below. Nights of 36°F, when frost can still settle on leaves in low, open spots, continue 32 days longer, to about March 10, and return around November 18. A 24°F night is unusual: 30% of winters had one.

July is the warmest month at Stockton Metro Airport, CA, averaging 95°F by day and 61°F at night; December is the coldest at 57°F and 38°F. From March to October the chance of a 32°F night stays under 10% each month. In spring, February still brings one in 54% of years.

Warmth for growing adds up to 5,040 growing degree days a year (base 50°F), more than at 65% of the 283 California stations. 38% of them (1,926) have built up by the end of June, and July adds the most, 873. Precipitation totals 13.5 inches a year, most in January (2.7") and least in July (0.0"); May to September bring 6% of it.

The nearest other station, Tracy Carbona, CA, 10 miles south of Lathrop, has a last frost 19 days later (February 25), a first frost 5 days earlier (November 26), a season 32 days shorter.

Measurable snow is rare here: only 0 of 22 winters from 1991 to 2020 recorded 0.1 inch or more at Tracy Carbona, CA, 9.9 miles away, so there is no typical first-snow date to plan around.

ZIP 95330 is 6 miles from Stockton Metro Airport, CA, which stands at 26 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 8 other ZIP codes share the station; its figures are presented in full for 95206 (Stockton). The 2023 USDA Plant Hardiness Zone Map lists ZIP 95330 in zone 9b, the band where the coldest night of the year averaged 25 to 30°F (-3.9 to -1.1°C) over 1991–2020; a zone describes winter lows, not frost dates.