USDA Hardiness Zone 9b
Frost Dates for 96019 — Shasta Lake, California
NOAA 1991–2020 normals from Shasta Dam, CA (1,075 ft), 3 miles northwest.
Updated
A freeze (32°F) reaches Shasta Lake in 87% of winters. When it does, the first fall frost comes around December 28 and the last spring frost around February 8; after March 28 the chance of another is under 9%.
- Last spring frost
- February 8
- First fall frost
- December 28
- Winters with a freeze
- 87%
- Hardiness zone
- 9b
50%, in freezing years
50%, in freezing years
32°F or below, 1991–2020
25 to 30°F (-3.9 to -1.1°C) coldest night
- First snow
- Rare
- Last snow
- Rare
- Winters with snow
- 15%
- Snow per year
- —
median, 1991–2020
median, 1991–2020
4 of 26 observed
NOAA normal
Frost risk by date in Shasta Lake
In the 87% of winters that bring a 32°F night, half of springs at Shasta Dam, CA see their last 32°F night by February 8; only one in ten is past it by December 26, and one in ten still has one after March 28. Counting the winters with no freeze at all, the risk of a 32°F night after March 28 is under 9% and after February 8 43%. The 48 days between the even-odds date and the one-in-ten date is wider than at 99% 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 December 28 in half of years, as early as December 1 one year in ten, and holds off past February 18 one year in ten. A hard freeze of 28°F is less common: it came in 27% of winters. The freeze-free season lasts 322 days in a typical year, longer than at 76% of the 219 California stations; it reaches 365 days one year in ten and falls short of 268 one year in ten. On average 6 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 39 days longer, to about March 19, and return around December 6. A 24°F night is unusual: 3% of winters had one.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Feb 6 | Feb 20 | Mar 1 | Mar 10 | Mar 19 | Mar 27 | Apr 1 | Apr 7 | Apr 16 |
| 32°F87% of yrs | Dec 26 | Jan 5 | Jan 16 | Jan 29 | Feb 8 | Feb 20 | Mar 1 | Mar 11 | Mar 28 |
| 28°F27% of yrs | too rare for a date | ||||||||
| 24°F3% of yrs | too rare for a date | ||||||||
| 20°F1% of yrs | too rare for a date | ||||||||
| 16°F1% of yrs | too rare for a date | ||||||||
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Nov 16 | Nov 23 | Nov 28 | Dec 2 | Dec 6 | Dec 10 | Dec 14 | Dec 21 | Dec 30 |
| 32°F87% of yrs | Dec 1 | Dec 9 | Dec 16 | Dec 21 | Dec 28 | Jan 1 | Jan 9 | Jan 24 | Feb 18 |
| 28°F27% of yrs | too rare for a date | ||||||||
| 24°F3% of yrs | too rare for a date | ||||||||
| 20°F1% of yrs | too rare for a date | ||||||||
| 16°F1% of yrs | too rare for a date | ||||||||
Freeze probabilities 1991–2020 at Shasta Dam, CA, from NOAA NCEI U.S. Climate Normals. Where a temperature is reached in fewer than 99.5% of years, the dates describe only the years that reach it. Not a forecast.
Frost risk on any date in 96019 →Compare Shasta Lake with another place →
Weather by month in Shasta Lake
July is the warmest month at Shasta Dam, CA, averaging 97°F by day and 69°F at night; December is the coldest at 54°F and 41°F. From April to November the chance of a 32°F night stays under 10% each month. In spring, February still brings one in 33% of years and March still brings one in 20% of years.
Warmth for growing adds up to 5,342 growing degree days a year (base 50°F), more than at 75% of the 283 California stations. 34% of them (1,841) have built up by the end of June, and July adds the most, 1,023. Precipitation totals 62.9 inches a year, most in December (12.0") and least in July (0.1"); May to September bring 8% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 55 | 41 | 10.5 | 46% | 2 | 40 |
| Feb | 59 | 42 | 11.4 | 33% | 1 | 72 |
| Mar | 63 | 44 | 9.2 | 20% | <1 | 156 |
| Apr | 70 | 48 | 4.6 | 7% | <1 | 273 |
| May | 79 | 55 | 2.9 | 0% | 0 | 533 |
| Jun | 88 | 63 | 1.5 | 0% | 0 | 768 |
| Jul | 97 | 69 | 0.1 | 0% | 0 | 1023 |
| Aug | 96 | 68 | 0.2 | 0% | 0 | 987 |
| Sep | 90 | 63 | 0.5 | 0% | 0 | 799 |
| Oct | 78 | 55 | 3.4 | 0% | 0 | 503 |
| Nov | 62 | 46 | 6.6 | 7% | <1 | 156 |
| Dec | 54 | 41 | 12.0 | 45% | 2 | 33 |
Monthly normals 1991–2020 at Shasta Dam, CA (1,075 ft), NOAA NCEI. "32°F night": chance of at least one in the month. GDD: growing degree days, base 50°F.
Compared with the next station
The nearest other station, Whiskeytown Rsvr, CA, 10 miles southwest of Shasta Lake and 220 feet higher, has a last frost 5 days later (February 13), a first frost 15 days earlier (December 13), a season 18 days shorter.
When it snows in Shasta Lake, California
Measurable snow is rare here: only 4 of 26 winters from 1991 to 2020 recorded 0.1 inch or more at Shasta Dam, CA, 3.3 miles away, so there is no typical first-snow date to plan around.
Where these figures come from
ZIP 96019 is 3 miles from Shasta Dam, CA, which stands at 1,075 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 96003 (Redding). The 2023 USDA Plant Hardiness Zone Map lists ZIP 96019 in zone 9b, the band where the coldest night of the year averaged 25 to 30°F (-3.9 to -1.1°C) over 1991–2020; a zone describes winter lows, not frost dates.
Frost dates across California →
Hardiness zone and temperature range: USDA Plant Hardiness Zone Map 2023 (USDA-ARS, Oregon State University), ZIP-code listing, unchanged. °C converted from °F by this site.
Thirty-year averages, not a forecast: check the forecast before planting out. How stations are matched and which pages are offered to search engines: methodology.