Frost Dates for 96113 — Herlong, California

Half of springs at Doyle 4 SSE, CA see their last 32°F night by May 21; only one in ten is past it by April 30, and one in ten still has one after June 11. Planting tender crops after May 31 leaves a 30% risk of a frost on them, after June 5 20%, and after June 11 10%. The 21 days between the even-odds date and the one-in-ten date is narrower than at 84% 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 October 1 in half of years, as early as September 9 one year in ten, and holds off past October 19 one year in ten. A hard freeze of 28°F follows 16 days later, around October 17; in spring the one-in-ten date for 28°F is May 26, 16 days before the 32°F one. The freeze-free season lasts 130 days in a typical year, shorter than at 95% of the 219 California stations; it reaches 159 days one year in ten and falls short of 104 one year in ten. On average 140 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 June 10, and return around September 12. Severe cold of 16°F or below comes every winter, usually between November 23 and February 18.

July is the warmest month at Doyle 4 SSE, CA, averaging 88°F by day and 51°F at night; December is the coldest at 42°F and 24°F. A freezing night is all but certain in every month from October to April (a 90% chance or more). From July to August the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 85% of years and June still brings one in 29% of years.

Warmth for growing adds up to 2,283 growing degree days a year (base 50°F), fewer than at 91% of the 283 California stations. 28% of them (634) have built up by the end of June, and July adds the most, 604. Precipitation totals 14.4 inches a year, most in December (2.5") and least in July (0.2"); May to September bring 18% of it.

The nearest other station, Portola, CA, 29 miles southwest of Herlong and 460 feet higher, has a last frost 21 days later (June 11), a first frost 21 days earlier (September 10), a season 39 days shorter.

The first measurable snow (0.1 inch or more) in Herlong usually arrives around November 30, and the last of the season around April 1. Those are the middle dates across the winters of 1991–2020 at Doyle 4 SSE, CA, 14 miles away: half of years saw snow earlier, half later. Every one of those winters saw snow. The last 32°F night of spring typically comes 50 days after the last snow.

ZIP 96113 is 14 miles from Doyle 4 SSE, CA, which stands at 4,390 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 96113 in zone 7a, the band where the coldest night of the year averaged 0 to 5°F (-17.8 to -15.0°C) over 1991–2020; a zone describes winter lows, not frost dates.