Frost Dates for 96025 — Dunsmuir, California

Half of springs at Dunsmuir Trtmt Pl, CA see their last 32°F night by April 23; only one in ten is past it by April 5, and one in ten still has one after May 12. Planting tender crops after May 1 leaves a 30% risk of a frost on them, after May 5 20%, and after May 12 10%. The 19 days between the even-odds date and the one-in-ten date is narrower than at 93% of the 220 California stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 27 in half of years, as early as October 9 one year in ten, and holds off past November 10 one year in ten. A hard freeze of 28°F follows 16 days later, around November 12; in spring the one-in-ten date for 28°F is April 21, 21 days before the 32°F one. The freeze-free season lasts 185 days in a typical year, shorter than at 85% of the 219 California stations; it reaches 208 days one year in ten and falls short of 158 one year in ten. On average 105 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 18 days longer, to about May 11, and return around October 9. Nights of 24°F, cold enough to damage hardier plants, come in 99% of winters and 16°F in 21%.

July is the warmest month at Dunsmuir Trtmt Pl, CA, averaging 90°F by day and 54°F at night; December is the coldest at 48°F and 30°F. A freezing night is all but certain in every month from November to April (a 90% chance or more). From June to September the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 30% of years.

Warmth for growing adds up to 2,829 growing degree days a year (base 50°F), fewer than at 87% of the 283 California stations. 31% of them (866) have built up by the end of June, and July adds the most, 680. Precipitation totals 63.4 inches a year, most in December (12.6") and least in July (0.2"); May to September bring 8% of it.

The nearest other station, Mt Shasta, CA, 7 miles north of Dunsmuir and 1,444 feet higher, has a last frost 22 days later (May 15), a first frost 21 days earlier (October 6), a season 42 days shorter.

The first measurable snow (0.1 inch or more) in Dunsmuir usually arrives around December 4, and the last of the season around March 17. Those are the middle dates across the winters of 1991–2020 at Dunsmuir Trtmt Pl, CA, 2.6 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 37 days after the last snow.

ZIP 96025 is 3 miles from Dunsmuir Trtmt Pl, CA, which stands at 2,169 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 96025 in zone 8a, the band where the coldest night of the year averaged 10 to 15°F (-12.2 to -9.4°C) over 1991–2020; a zone describes winter lows, not frost dates.