Frost Dates for 96041 — Hayfork, California

Half of springs at Big Bar 4 E, CA see their last 32°F night by April 16; only one in ten is past it by March 23, and one in ten still has one after May 3. Planting tender crops after April 24 leaves a 30% risk of a frost on them, after April 28 20%, and after May 3 10%. The 17 days between the even-odds date and the one-in-ten date is narrower than at 96% of the 220 California stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 31 in half of years, as early as October 13 one year in ten, and holds off past November 26 one year in ten. A hard freeze of 28°F follows 19 days later, around November 19; in spring the one-in-ten date for 28°F is April 16, 17 days before the 32°F one. The freeze-free season lasts 197 days in a typical year, shorter than at 81% of the 219 California stations; it reaches 231 days one year in ten and falls short of 170 one year in ten. On average 59 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 20 days longer, to about May 6, and return around October 14. Nights of 24°F, cold enough to damage hardier plants, come in 88% of winters and 16°F in 14%.

July is the warmest month at Big Bar 4 E, CA, averaging 97°F by day and 53°F at night; December is the coldest at 48°F and 34°F. A freezing night is all but certain in every month from December to March (a 90% chance or more). From June to September the chance of a 32°F night stays under 10% each month. In spring, April still brings one in 79% of years and May still brings one in 15% of years.

Warmth for growing adds up to 3,431 growing degree days a year (base 50°F), fewer than at 73% of the 283 California stations. 32% of them (1,098) have built up by the end of June, and July adds the most, 770. Precipitation totals 35.8 inches a year, most in December (7.2") and least in July (0.2"); May to September bring 9% of it.

The nearest other station, Weaverville, CA, 19 miles northeast of Hayfork and 805 feet higher, has a last frost 17 days later (May 3), a first frost 20 days earlier (October 11), a season 38 days shorter.

The first measurable snow (0.1 inch or more) in Hayfork usually arrives around December 23, and the last of the season around March 1. Those are the middle dates across the winters of 1991–2020 at Big Bar 4 E, CA, 15 miles away: half of years saw snow earlier, half later. Snow fell in 70% of those winters. The last 32°F night of spring typically comes 46 days after the last snow.

ZIP 96041 is 15 miles from Big Bar 4 E, CA, which stands at 1,253 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 96041 in zone 8b, the band where the coldest night of the year averaged 15 to 20°F (-9.4 to -6.7°C) over 1991–2020; a zone describes winter lows, not frost dates.