USDA Hardiness Zone 10a
Frost Dates for 91352 — Sun Valley, California
NOAA 1991–2020 normals from Burbank Glendale Pasadena Airport, CA (741 ft), 2 miles southeast.
Updated
Frost is not a yearly event in Sun Valley: a night at or below 32°F came in 21% of the winters of 1991–2020 at Burbank Glendale Pasadena Airport, CA, and a 36°F night, cold enough for frost on exposed leaves, in 83%. There is no reliable "last frost date" here; most years have none.
- Winters with a freeze
- 21%
- Winters with 36°F
- 83%
- Coldest month low
- 44°F
- Hardiness zone
- 10a
32°F or below, 1991–2020
frost possible on leaves
average, December
30 to 35°F (-1.1 to 1.7°C) coldest night
- First snow
- Rare
- Last snow
- Rare
- Winters with snow
- 0%
- Snow per year
- 0"
median, 1991–2020
median, 1991–2020
0 of 20 observed
NOAA normal
Frost risk by date in Sun Valley
At Burbank Glendale Pasadena Airport, CA, 2 miles southeast of Sun Valley, 21% of the winters of 1991–2020 had at least one night at or below 32°F, 1% reached 28°F. Nights of 36°F, enough for frost on exposed leaves, are more common (83% of winters) and, when they come, fall between about December 18 and January 11. December is the month most likely to bring one: a 12% chance in a given year. 62 of the 283 other California stations behind this site's ZIP pages freeze in fewer than half of winters too.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F83% of yrs | Dec 16 | Dec 25 | Dec 31 | Jan 5 | Jan 11 | Jan 18 | Jan 29 | Feb 8 | Feb 21 |
| 32°F21% of yrs | too rare for a date | ||||||||
| 28°F1% of yrs | too rare for a date | ||||||||
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F83% of yrs | Nov 30 | Dec 7 | Dec 11 | Dec 15 | Dec 18 | Dec 23 | Dec 28 | Jan 3 | Jan 20 |
| 32°F21% of yrs | too rare for a date | ||||||||
| 28°F1% of yrs | too rare for a date | ||||||||
Freeze probabilities 1991–2020 at Burbank Glendale Pasadena Airport, 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 91352 →Compare Sun Valley with another place →
Weather by month in Sun Valley
August is the warmest month at Burbank Glendale Pasadena Airport, CA, averaging 89°F by day and 65°F at night; December is the coldest at 66°F and 44°F. From January to November the chance of a 32°F night stays under 10% each month.
Warmth for growing adds up to 5,593 growing degree days a year (base 50°F), more than at 82% of the 283 California stations. 39% of them (2,155) have built up by the end of June, and August adds the most, 834. Precipitation totals 13.9 inches a year, most in February (4.0") and least in July (0.0"); May to September bring 4% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 67 | 45 | 3.0 | 9% | <1 | 202 |
| Feb | 67 | 46 | 4.0 | 0% | 0 | 193 |
| Mar | 70 | 49 | 2.4 | 0% | 0 | 290 |
| Apr | 73 | 52 | 0.7 | 0% | 0 | 370 |
| May | 76 | 57 | 0.3 | 0% | 0 | 498 |
| Jun | 80 | 60 | 0.1 | 0% | 0 | 603 |
| Jul | 87 | 65 | 0.0 | 0% | 0 | 794 |
| Aug | 89 | 65 | 0.0 | 0% | 0 | 834 |
| Sep | 87 | 63 | 0.1 | 0% | 0 | 742 |
| Oct | 79 | 58 | 0.6 | 0% | 0 | 572 |
| Nov | 73 | 49 | 0.7 | 0% | 0 | 324 |
| Dec | 66 | 44 | 2.0 | 12% | <1 | 172 |
Monthly normals 1991–2020 at Burbank Glendale Pasadena Airport, CA (741 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, Burbank Valley Pump Plt, CA, 3 miles southeast of Sun Valley, has a 32°F night in 55% of winters against 21% here, and a coolest-month low 2°F colder (42°F).
When it snows in Sun Valley, California
Measurable snow is rare here: only 0 of 20 winters from 1991 to 2020 recorded 0.1 inch or more at Burbank Valley Pump Plt, CA, 3 miles away, so there is no typical first-snow date to plan around.
Where these figures come from
ZIP 91352 is 2 miles from Burbank Glendale Pasadena Airport, CA, which stands at 741 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 4 other ZIP codes share the station; its figures are presented in full for 91605 (North Hollywood). The 2023 USDA Plant Hardiness Zone Map lists ZIP 91352 in zone 10a, the band where the coldest night of the year averaged 30 to 35°F (-1.1 to 1.7°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.