USDA Hardiness Zone 9b
Frost Dates for 92583 — San Jacinto, California
NOAA 1991–2020 normals from San Jacinto, CA (1,525 ft), 2 miles west.
Updated
In San Jacinto, the last spring frost (32°F) is around January 31 in half of years and has passed by February 28 in nine years out of ten. The first fall frost comes around December 10, as early as November 22 one year in ten, leaving a typical freeze-free season of 315 days (NOAA, San Jacinto, CA).
- Last spring frost
- January 31
- First fall frost
- December 10
- Growing season
- 315 days
- Hardiness zone
- 9b
50% probability
50% probability
freeze-free, 50%
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 20 observed
NOAA normal
Frost risk by date in San Jacinto
Half of springs at San Jacinto, CA see their last 32°F night by January 31; only one in ten is past it by December 31, and one in ten still has one after February 28. Planting tender crops after February 14 leaves a 30% risk of a frost on them, after February 21 20%, and after February 28 10%. The 28 days between the even-odds date and the one-in-ten date is narrower than at 60% 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 10 in half of years, as early as November 22 one year in ten, and holds off past January 6 one year in ten. A hard freeze of 28°F follows 11 days later, around December 21; in spring the one-in-ten date for 28°F is January 29, 30 days before the 32°F one. The freeze-free season lasts 315 days in a typical year, longer than at 72% of the 219 California stations; it reaches 348 days one year in ten and falls short of 274 one year in ten. On average 15 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 33 days longer, to about March 5, and return around November 24. A 24°F night is unusual: 11% of winters had one.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Feb 6 | Feb 17 | Feb 23 | Feb 28 | Mar 5 | Mar 12 | Mar 20 | Mar 29 | Apr 8 |
| 32°F97% of yrs | Dec 31 | Jan 6 | Jan 17 | Jan 25 | Jan 31 | Feb 6 | Feb 14 | Feb 21 | Feb 28 |
| 28°F59% of yrs | Dec 11 | Dec 19 | Dec 25 | Dec 31 | Jan 3 | Jan 7 | Jan 12 | Jan 21 | Jan 29 |
| 24°F11% of yrs | too rare for a date | ||||||||
| 20°F0% of yrs | too rare for a date | ||||||||
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Nov 5 | Nov 12 | Nov 17 | Nov 21 | Nov 24 | Nov 28 | Dec 2 | Dec 6 | Dec 12 |
| 32°F97% of yrs | Nov 22 | Nov 29 | Dec 2 | Dec 6 | Dec 10 | Dec 14 | Dec 18 | Dec 26 | Jan 6 |
| 28°F59% of yrs | Dec 2 | Dec 8 | Dec 13 | Dec 17 | Dec 21 | Dec 26 | Dec 30 | Jan 4 | Jan 15 |
| 24°F11% of yrs | too rare for a date | ||||||||
| 20°F0% of yrs | too rare for a date | ||||||||
Freeze probabilities 1991–2020 at San Jacinto, 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 92583 →Compare San Jacinto with another place →
Weather by month in San Jacinto
August is the warmest month at San Jacinto, CA, averaging 97°F by day and 64°F at night; December is the coldest at 65°F and 39°F. From March to October the chance of a 32°F night stays under 10% each month. In spring, February still brings one in 42% of years.
Warmth for growing adds up to 5,606 growing degree days a year (base 50°F), more than at 83% of the 283 California stations. 37% of them (2,056) have built up by the end of June, and August adds the most, 942. Precipitation totals 12.4 inches a year, most in February (2.8") and least in June (0.1"); May to September bring 10% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 66 | 40 | 2.7 | 72% | 4 | 124 |
| Feb | 66 | 42 | 2.8 | 42% | 2 | 131 |
| Mar | 70 | 45 | 1.7 | 7% | 1 | 245 |
| Apr | 74 | 48 | 0.8 | 2% | <1 | 339 |
| May | 80 | 53 | 0.5 | 0% | 0 | 523 |
| Jun | 89 | 58 | 0.1 | 0% | 0 | 695 |
| Jul | 95 | 64 | 0.2 | 0% | 0 | 910 |
| Aug | 97 | 64 | 0.1 | 0% | 0 | 942 |
| Sep | 92 | 61 | 0.3 | 0% | 0 | 787 |
| Oct | 82 | 53 | 0.5 | 0% | <1 | 543 |
| Nov | 73 | 44 | 0.8 | 23% | 1 | 265 |
| Dec | 65 | 39 | 1.9 | 78% | 7 | 103 |
Monthly normals 1991–2020 at San Jacinto, CA (1,525 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, Hemet, CA, 5 miles southeast of San Jacinto and 286 feet higher, has a last frost 21 days earlier (January 10), a first frost 13 days later (December 23), a season 35 days longer.
When it snows in San Jacinto, California
Measurable snow is rare here: only 0 of 20 winters from 1991 to 2020 recorded 0.1 inch or more at San Jacinto, CA, 1.5 miles away, so there is no typical first-snow date to plan around.
Planting calendar for 92583
| When | What to do |
|---|---|
| November 22 – December 6 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| December 6 – December 20 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| January 3 – January 17 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| January 31 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by September 17 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by November 26 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| December 10 onward | Plant garlic, mulch beds, lift tender bulbsGarlic wants a cold spell; bare soil loses structure over winter. |
The weeks before and after the 50% dates are general rules of thumb, not NOAA figures; a seed packet gives the timing for each variety.
Where these figures come from
ZIP 92583 is 2 miles from San Jacinto, CA, which stands at 1,525 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 8 other ZIP codes share the station; its figures are presented in full for 92223 (Beaumont). The 2023 USDA Plant Hardiness Zone Map lists ZIP 92583 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.