USDA Hardiness Zone 9b
Frost Dates for 95111 — San Jose, California
NOAA 1991–2020 normals from San Jose, CA (67 ft), 6 miles northwest.
Updated
A freeze (32°F) reaches San Jose in 56% of winters. When it does, the first fall frost comes around December 25 and the last spring frost around January 2; after January 23 the chance of another is under 6%.
- Last spring frost
- January 2
- First fall frost
- December 25
- Winters with a freeze
- 56%
- 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
- 0%
- Snow per year
- 0"
median, 1991–2020
median, 1991–2020
0 of 17 observed
NOAA normal
Frost risk by date in San Jose
In the 56% of winters that bring a 32°F night, half of springs at San Jose, CA see their last 32°F night by January 2; only one in ten is past it by December 14, and one in ten still has one after January 23. Counting the winters with no freeze at all, the risk of a 32°F night after January 23 is under 6% and after January 2 28%. The 21 days between the even-odds date and the one-in-ten date is narrower than at 84% 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 25 in half of years, as early as December 4 one year in ten, and holds off past January 14 one year in ten. A hard freeze of 28°F is less common: it came in 8% of winters. The freeze-free season lasts 362 days in a typical year, longer than at 98% of the 219 California stations; it reaches 365 days one year in ten and falls short of 335 one year in ten. On average 2 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 24 days longer, to about January 26, and return around December 10. No night reached 24°F in 1991–2020.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F95% of yrs | Dec 27 | Jan 2 | Jan 10 | Jan 19 | Jan 26 | Feb 1 | Feb 7 | Feb 17 | Feb 27 |
| 32°F56% of yrs | Dec 14 | Dec 22 | Dec 27 | Dec 31 | Jan 2 | Jan 6 | Jan 10 | Jan 16 | Jan 23 |
| 28°F8% of yrs | too rare for a date | ||||||||
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F95% of yrs | Nov 22 | Nov 30 | Dec 2 | Dec 6 | Dec 10 | Dec 14 | Dec 21 | Dec 28 | Jan 4 |
| 32°F56% of yrs | Dec 4 | Dec 9 | Dec 14 | Dec 19 | Dec 25 | Dec 28 | Jan 1 | Jan 5 | Jan 14 |
| 28°F8% of yrs | too rare for a date | ||||||||
Freeze probabilities 1991–2020 at San Jose, 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 95111 →Compare San Jose with another place →
Weather by month in San Jose
August is the warmest month at San Jose, CA, averaging 83°F by day and 60°F at night; December is the coldest at 59°F and 43°F. From February to November the chance of a 32°F night stays under 10% each month.
Warmth for growing adds up to 4,309 growing degree days a year (base 50°F), fewer than at 54% of the 283 California stations. 40% of them (1,714) have built up by the end of June, and August adds the most, 659. Precipitation totals 16.1 inches a year, most in February (3.2") and least in July (0.0"); May to September bring 5% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 59 | 43 | 3.0 | 32% | 1 | 75 |
| Feb | 63 | 45 | 3.2 | 0% | 0 | 126 |
| Mar | 66 | 48 | 2.6 | 0% | 0 | 223 |
| Apr | 70 | 50 | 1.2 | 0% | 0 | 298 |
| May | 75 | 53 | 0.5 | 0% | 0 | 437 |
| Jun | 80 | 57 | 0.2 | 0% | 0 | 556 |
| Jul | 82 | 59 | 0.0 | 0% | 0 | 640 |
| Aug | 83 | 60 | 0.0 | 0% | 0 | 659 |
| Sep | 81 | 58 | 0.1 | 0% | 0 | 594 |
| Oct | 75 | 54 | 0.8 | 0% | 0 | 440 |
| Nov | 65 | 47 | 1.4 | 2% | <1 | 191 |
| Dec | 59 | 43 | 3.1 | 37% | 1 | 70 |
Monthly normals 1991–2020 at San Jose, CA (67 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, San Jose, CA, 7 miles northwest of San Jose, has a last frost 10 days later (January 12), a first frost 3 days earlier (December 22), a season 15 days shorter.
When it snows in San Jose, California
Measurable snow is rare here: only 0 of 17 winters from 1991 to 2020 recorded 0.1 inch or more at San Jose, CA, 6.2 miles away, so there is no typical first-snow date to plan around.
Where these figures come from
ZIP 95111 is 6 miles from San Jose, CA, which stands at 67 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 15 other ZIP codes share the station; its figures are presented in full for 95127 (San Jose). The 2023 USDA Plant Hardiness Zone Map lists ZIP 95111 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.