Frost Dates for 96114 — Janesville, California

Half of springs at Susanville 2SW, CA see their last 32°F night by May 16; only one in ten is past it by April 29, and one in ten still has one after June 5. Planting tender crops after May 24 leaves a 30% risk of a frost on them, after May 31 20%, and after June 5 10%. The 20 days between the even-odds date and the one-in-ten date is narrower than at 88% of the 220 California stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 8 in half of years, as early as September 25 one year in ten, and holds off past October 22 one year in ten. A hard freeze of 28°F follows 13 days later, around October 21; in spring the one-in-ten date for 28°F is May 17, 19 days before the 32°F one. The freeze-free season lasts 143 days in a typical year, shorter than at 93% of the 219 California stations; it reaches 167 days one year in ten and falls short of 118 one year in ten. On average 149 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 19 days longer, to about June 4, and return around September 26. Severe cold of 16°F or below comes every winter, usually between November 26 and February 23.

July is the warmest month at Susanville 2SW, CA, averaging 88°F by day and 53°F at night; December is the coldest at 43°F and 22°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 84% of years and June still brings one in 18% of years.

Warmth for growing adds up to 2,376 growing degree days a year (base 50°F), fewer than at 89% of the 283 California stations. 27% of them (638) have built up by the end of June, and July adds the most, 637. Precipitation totals 13.0 inches a year, most in January (2.4") and least in August (0.1"); May to September bring 13% of it.

The nearest other station, Canyon Dam, CA, 31 miles west of Janesville and 348 feet higher, has a last frost 2 days later (May 18), the same first-frost date.

The first measurable snow (0.1 inch or more) in Janesville usually arrives around December 8, and the last of the season around March 9. Those are the middle dates across the winters of 1991–2020 at Susanville 2SW, CA, 11.3 miles away: half of years saw snow earlier, half later. Snow fell in 95% of those winters. The last 32°F night of spring typically comes 68 days after the last snow.

ZIP 96114 is 11 miles from Susanville 2SW, CA, which stands at 4,212 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station; its figures are presented in full for 96130 (Susanville). The 2023 USDA Plant Hardiness Zone Map lists ZIP 96114 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.