Frost Dates for 93927 — Greenfield, California

Half of springs at King City, CA see their last 32°F night by February 23; only one in ten is past it by January 19, and one in ten still has one after March 31. Planting tender crops after March 6 leaves a 30% risk of a frost on them, after March 16 20%, and after March 31 10%. The 36 days between the even-odds date and the one-in-ten date is wider than at 75% 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 November 22 in half of years, as early as November 1 one year in ten, and holds off past December 11 one year in ten. A hard freeze of 28°F follows 14 days later, around December 6; in spring the one-in-ten date for 28°F is February 21, 38 days before the 32°F one. The freeze-free season lasts 271 days in a typical year, shorter than at 55% of the 219 California stations; it reaches 308 days one year in ten and falls short of 233 one year in ten. On average 27 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 43 days longer, to about April 7, and return around November 4. Nights of 24°F, cold enough to damage hardier plants, come in 54% of winters and 16°F in 1%.

August is the warmest month at King City, CA, averaging 85°F by day and 54°F at night; December is the coldest at 62°F and 37°F. A freezing night is all but certain in December (a 90% chance or more). From May to October the chance of a 32°F night stays under 10% each month. In spring, February still brings one in 70% of years and March still brings one in 29% of years and April still brings one in 10% of years.

Warmth for growing adds up to 3,940 growing degree days a year (base 50°F), fewer than at 62% of the 283 California stations. 39% of them (1,554) have built up by the end of June, and August adds the most, 603. Precipitation totals 11.8 inches a year, most in February (2.5") and least in June (0.0"); May to September bring 4% of it.

The nearest other station, Pinnacles Nm, CA, 14 miles northeast of Greenfield and 987 feet higher, has a last frost 59 days later (April 23), a first frost 19 days earlier (November 3), a season 82 days shorter.

Measurable snow is rare here: only 1 of 20 winters from 1991 to 2020 recorded 0.1 inch or more at King City, CA, 10.7 miles away, so there is no typical first-snow date to plan around.

ZIP 93927 is 11 miles from King City, CA, which stands at 320 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 93927 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.