Frost Dates for 93675 — Squaw Valley, California

Half of springs at Grant Grove, CA see their last 32°F night by June 1; only one in ten is past it by May 11, and one in ten still has one after June 15. Planting tender crops after June 5 leaves a 30% risk of a frost on them, after June 9 20%, and after June 15 10%. The 14 days between the even-odds date and the one-in-ten date is narrower than at 100% of the 220 California stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 7 in half of years, as early as September 19 one year in ten, and holds off past October 30 one year in ten. A hard freeze of 28°F follows 14 days later, around October 21; in spring the one-in-ten date for 28°F is June 6, 9 days before the 32°F one. The freeze-free season lasts 132 days in a typical year, shorter than at 95% of the 219 California stations; it reaches 160 days one year in ten and falls short of 108 one year in ten. On average 137 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 8 days longer, to about June 9, and return around September 25. Severe cold of 16°F or below comes every winter, usually between December 6 and March 28.

July is the warmest month at Grant Grove, CA, averaging 79°F by day and 53°F at night; December is the coldest at 46°F and 25°F. A freezing night is all but certain in every month from November to May (a 90% chance or more). From July to August the chance of a 32°F night stays under 10% each month. In spring, June still brings one in 50% of years.

Warmth for growing adds up to 1,819 growing degree days a year (base 50°F), fewer than at 95% of the 283 California stations. 21% of them (391) have built up by the end of June, and July adds the most, 486. Precipitation totals 41.7 inches a year, most in January (8.0") and least in August (0.2"); May to September bring 6% of it.

The nearest other station, Lemon Cove, CA, 25 miles south of Squaw Valley and 6,067 feet lower, has a last frost 116 days earlier (February 5), a first frost 62 days later (December 8), a season 175 days longer.

The first measurable snow (0.1 inch or more) in Squaw Valley usually arrives around November 1, and the last of the season around May 13. Those are the middle dates across the winters of 1991–2020 at Grant Grove, CA, 12.4 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 19 days after the last snow.

ZIP 93675 is 12 miles from Grant Grove, CA, which stands at 6,580 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 93675 in zone 9a, the band where the coldest night of the year averaged 20 to 25°F (-6.7 to -3.9°C) over 1991–2020; a zone describes winter lows, not frost dates.