USDA Hardiness Zone 9b
Frost Dates for 92570 — Perris, California
NOAA 1991–2020 normals from Elsinore, CA (1,268 ft), 7 miles south.
Updated
In Perris, the last spring frost (32°F) is around January 28 in half of years and has passed by February 27 in nine years out of ten. The first fall frost comes around December 18, as early as December 1 one year in ten, leaving a typical freeze-free season of 329 days (NOAA, Elsinore, CA).
- Last spring frost
- January 28
- First fall frost
- December 18
- Growing season
- 329 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
- 10%
- Snow per year
- 0.2"
median, 1991–2020
median, 1991–2020
2 of 20 observed
NOAA normal
Frost risk by date in Perris
Half of springs at Elsinore, CA see their last 32°F night by January 28; only one in ten is past it by December 24, and one in ten still has one after February 27. Planting tender crops after February 10 leaves a 30% risk of a frost on them, after February 19 20%, and after February 27 10%. The 30 days between the even-odds date and the one-in-ten date is narrower than at 48% 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 18 in half of years, as early as December 1 one year in ten, and holds off past January 24 one year in ten. A hard freeze of 28°F is less common: it came in 38% of winters. The freeze-free season lasts 329 days in a typical year, longer than at 81% of the 219 California stations; it reaches 361 days one year in ten and falls short of 287 one year in ten. On average 9 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 31 days longer, to about February 28, and return around December 2. A 24°F night is unusual: 2% of winters had one.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Jan 29 | Feb 10 | Feb 18 | Feb 25 | Feb 28 | Mar 5 | Mar 12 | Mar 21 | Apr 2 |
| 32°F91% of yrs | Dec 24 | Jan 2 | Jan 9 | Jan 18 | Jan 28 | Feb 4 | Feb 10 | Feb 19 | Feb 27 |
| 28°F38% of yrs | too rare for a date | ||||||||
| 24°F2% of yrs | too rare for a date | ||||||||
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Nov 15 | Nov 22 | Nov 27 | Nov 30 | Dec 2 | Dec 5 | Dec 9 | Dec 13 | Dec 18 |
| 32°F91% of yrs | Dec 1 | Dec 6 | Dec 10 | Dec 13 | Dec 18 | Dec 22 | Dec 28 | Jan 4 | Jan 24 |
| 28°F38% of yrs | too rare for a date | ||||||||
| 24°F2% of yrs | too rare for a date | ||||||||
Freeze probabilities 1991–2020 at Elsinore, 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 92570 →Compare Perris with another place →
Weather by month in Perris
August is the warmest month at Elsinore, CA, averaging 98°F by day and 65°F at night; December is the coldest at 65°F and 40°F. From March to November the chance of a 32°F night stays under 10% each month. In spring, February still brings one in 39% of years.
Warmth for growing adds up to 5,940 growing degree days a year (base 50°F), more than at 88% of the 283 California stations. 38% of them (2,233) have built up by the end of June, and August adds the most, 970. Precipitation totals 11.8 inches a year, most in January (3.0") and least in June (0.1"); May to September bring 7% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 66 | 42 | 3.0 | 56% | 3 | 144 |
| Feb | 67 | 43 | 2.9 | 39% | 1 | 154 |
| Mar | 72 | 46 | 1.5 | 6% | <1 | 274 |
| Apr | 77 | 49 | 0.5 | 0% | <1 | 379 |
| May | 82 | 54 | 0.2 | 0% | 0 | 555 |
| Jun | 90 | 58 | 0.1 | 0% | 0 | 728 |
| Jul | 97 | 64 | 0.2 | 0% | 0 | 939 |
| Aug | 98 | 65 | 0.1 | 0% | 0 | 970 |
| Sep | 93 | 61 | 0.2 | 0% | 0 | 816 |
| Oct | 83 | 54 | 0.5 | 0% | 0 | 574 |
| Nov | 73 | 46 | 0.6 | 8% | 1 | 292 |
| Dec | 65 | 40 | 2.0 | 66% | 4 | 116 |
Monthly normals 1991–2020 at Elsinore, CA (1,268 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, Riverside Fire Stn 3, CA, 13 miles northwest of Perris and 428 feet lower, has a last frost 19 days earlier (January 9), a first frost 7 days later (December 25), a season 24 days longer.
When it snows in Perris, California
Measurable snow is rare here: only 2 of 20 winters from 1991 to 2020 recorded 0.1 inch or more at Elsinore, CA, 7.3 miles away, so there is no typical first-snow date to plan around.
Planting calendar for 92570
| When | What to do |
|---|---|
| November 19 – December 3 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| December 3 – December 17 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| December 31 – January 14 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| January 28 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by September 25 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by December 4 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| December 18 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 92570 is 7 miles from Elsinore, CA, which stands at 1,268 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 9 other ZIP codes share the station; its figures are presented in full for 92530 (Lake Elsinore). The 2023 USDA Plant Hardiness Zone Map lists ZIP 92570 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.