USDA Hardiness Zone 9b
Frost Dates for 93271 — Three Rivers, California
NOAA 1991–2020 normals from Three Rivers Edison Ph 1, CA (1,140 ft), 2 miles north.
Updated
In Three Rivers, the last spring frost (32°F) is around March 16 in half of years and has passed by April 14 in nine years out of ten. The first fall frost comes around November 26, as early as November 5 one year in ten, leaving a typical freeze-free season of 249 days (NOAA, Three Rivers Edison Ph 1, CA).
- Last spring frost
- March 16
- First fall frost
- November 26
- Growing season
- 249 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 18 observed
NOAA normal
Frost risk by date in Three Rivers
Half of springs at Three Rivers Edison Ph 1, CA see their last 32°F night by March 16; only one in ten is past it by February 5, and one in ten still has one after April 14. Planting tender crops after April 1 leaves a 30% risk of a frost on them, after April 7 20%, and after April 14 10%. The 29 days between the even-odds date and the one-in-ten date is narrower than at 52% 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 November 26 in half of years, as early as November 5 one year in ten, and holds off past December 12 one year in ten. A hard freeze of 28°F follows 15 days later, around December 11; in spring the one-in-ten date for 28°F is March 18, 27 days before the 32°F one. The freeze-free season lasts 249 days in a typical year, shorter than at 67% of the 219 California stations; it reaches 294 days one year in ten and falls short of 216 one year in ten. On average 30 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 28 days longer, to about April 13, and return around November 10. A 24°F night is unusual: 43% of winters had one.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Mar 21 | Mar 31 | Apr 5 | Apr 9 | Apr 13 | Apr 17 | Apr 21 | Apr 27 | May 4 |
| 32°F | Feb 5 | Feb 19 | Feb 28 | Mar 9 | Mar 16 | Mar 25 | Apr 1 | Apr 7 | Apr 14 |
| 28°F96% of yrs | Dec 24 | Jan 3 | Jan 14 | Jan 23 | Jan 30 | Feb 6 | Feb 15 | Feb 28 | Mar 18 |
| 24°F43% of yrs | too rare for a date | ||||||||
| 20°F4% of yrs | too rare for a date | ||||||||
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 21 | Oct 29 | Nov 3 | Nov 7 | Nov 10 | Nov 14 | Nov 17 | Nov 20 | Nov 25 |
| 32°F | Nov 5 | Nov 13 | Nov 18 | Nov 23 | Nov 26 | Nov 29 | Dec 2 | Dec 6 | Dec 12 |
| 28°F96% of yrs | Nov 22 | Nov 28 | Dec 2 | Dec 7 | Dec 11 | Dec 16 | Dec 20 | Dec 26 | Jan 11 |
| 24°F43% of yrs | too rare for a date | ||||||||
| 20°F4% of yrs | too rare for a date | ||||||||
Freeze probabilities 1991–2020 at Three Rivers Edison Ph 1, 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 93271 →Compare Three Rivers with another place →
Weather by month in Three Rivers
July is the warmest month at Three Rivers Edison Ph 1, CA, averaging 97°F by day and 65°F at night; December is the coldest at 58°F and 35°F. A freezing night is all but certain in every month from December to January (a 90% chance or more). From May to October the chance of a 32°F night stays under 10% each month. In spring, February still brings one in 79% of years and March still brings one in 54% of years and April still brings one in 30% of years.
Warmth for growing adds up to 4,996 growing degree days a year (base 50°F), more than at 64% of the 283 California stations. 35% of them (1,755) have built up by the end of June, and July adds the most, 967. Precipitation totals 22.8 inches a year, most in January (4.8") and least in August (0.0"); May to September bring 7% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 58 | 36 | 4.8 | 95% | 9 | 26 |
| Feb | 62 | 38 | 3.6 | 79% | 4 | 61 |
| Mar | 67 | 41 | 4.1 | 54% | 2 | 157 |
| Apr | 73 | 44 | 2.4 | 30% | 1 | 264 |
| May | 82 | 51 | 1.0 | 1% | 0 | 504 |
| Jun | 91 | 58 | 0.3 | 0% | 0 | 743 |
| Jul | 97 | 65 | 0.1 | 0% | 0 | 967 |
| Aug | 96 | 64 | 0.0 | 0% | 0 | 935 |
| Sep | 92 | 58 | 0.2 | 0% | 0 | 747 |
| Oct | 79 | 49 | 0.9 | 6% | <1 | 441 |
| Nov | 66 | 40 | 1.7 | 61% | 4 | 129 |
| Dec | 58 | 35 | 3.7 | 98% | 11 | 23 |
Monthly normals 1991–2020 at Three Rivers Edison Ph 1, CA (1,140 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, Lemon Cove, CA, 10 miles west of Three Rivers and 627 feet lower, has a last frost 39 days earlier (February 5), a first frost 12 days later (December 8), a season 58 days longer.
When it snows in Three Rivers, California
Measurable snow is rare here: only 0 of 18 winters from 1991 to 2020 recorded 0.1 inch or more at Three Rivers Edison Ph 1, CA, 2.3 miles away, so there is no typical first-snow date to plan around.
Planting calendar for 93271
| When | What to do |
|---|---|
| January 5 – January 19 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| January 19 – February 2 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| February 16 – March 2 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| March 16 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by September 3 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by November 12 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| November 26 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 93271 is 2 miles from Three Rivers Edison Ph 1, CA, which stands at 1,140 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 93271 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.