USDA Hardiness Zone 9b
Frost Dates for 92225 — Blythe, California
NOAA 1991–2020 normals from Blythe, CA (268 ft), 2 miles southeast.
Updated
In Blythe, the last spring frost (32°F) is around January 25 in half of years and has passed by February 24 in nine years out of ten. The first fall frost comes around December 12, as early as November 28 one year in ten, leaving a typical freeze-free season of 325 days (NOAA, Blythe, CA).
- Last spring frost
- January 25
- First fall frost
- December 12
- Growing season
- 325 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 22 observed
NOAA normal
Frost risk by date in Blythe
Half of springs at Blythe, CA see their last 32°F night by January 25; only one in ten is past it by December 29, and one in ten still has one after February 24. Planting tender crops after February 8 leaves a 30% risk of a frost on them, after February 15 20%, and after February 24 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 12 in half of years, as early as November 28 one year in ten, and holds off past January 3 one year in ten. A hard freeze of 28°F follows 10 days later, around December 22; in spring the one-in-ten date for 28°F is January 30, 25 days before the 32°F one. The freeze-free season lasts 325 days in a typical year, longer than at 78% of the 219 California stations; it reaches 353 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 27 days longer, to about February 21, and return around December 1. A 24°F night is unusual: 9% of winters had one.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Jan 25 | Feb 4 | Feb 11 | Feb 16 | Feb 21 | Feb 25 | Feb 28 | Mar 4 | Mar 10 |
| 32°F96% of yrs | Dec 29 | Jan 3 | Jan 9 | Jan 16 | Jan 25 | Feb 1 | Feb 8 | Feb 15 | Feb 24 |
| 28°F62% of yrs | Dec 10 | Dec 18 | Dec 23 | Dec 26 | Dec 30 | Jan 1 | Jan 5 | Jan 12 | Jan 30 |
| 24°F9% of yrs | too rare for a date | ||||||||
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Nov 16 | Nov 22 | Nov 26 | Nov 29 | Dec 1 | Dec 3 | Dec 6 | Dec 11 | Dec 16 |
| 32°F96% of yrs | Nov 28 | Dec 2 | Dec 5 | Dec 9 | Dec 12 | Dec 15 | Dec 20 | Dec 25 | Jan 3 |
| 28°F62% of yrs | Dec 5 | Dec 10 | Dec 14 | Dec 18 | Dec 22 | Dec 25 | Dec 28 | Jan 1 | Jan 11 |
| 24°F9% of yrs | too rare for a date | ||||||||
Freeze probabilities 1991–2020 at Blythe, 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 92225 →Compare Blythe with another place →
Weather by month in Blythe
July is the warmest month at Blythe, CA, averaging 110°F by day and 78°F at night; December is the coldest at 66°F and 38°F. From March to October the chance of a 32°F night stays under 10% each month. In spring, February still brings one in 37% of years.
Warmth for growing adds up to 8,641 growing degree days a year (base 50°F), more than at 97% of the 283 California stations. 42% of them (3,593) have built up by the end of June, and July adds the most, 1,361. Precipitation totals 3.7 inches a year, most in January (0.6") and least in June (0.0"); May to September bring 30% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 69 | 40 | 0.6 | 68% | 3 | 161 |
| Feb | 73 | 43 | 0.6 | 37% | 1 | 235 |
| Mar | 81 | 49 | 0.4 | 5% | <1 | 450 |
| Apr | 89 | 55 | 0.1 | 0% | 0 | 653 |
| May | 98 | 63 | 0.1 | 0% | 0 | 946 |
| Jun | 106 | 71 | 0.0 | 0% | 0 | 1149 |
| Jul | 110 | 78 | 0.2 | 0% | 0 | 1361 |
| Aug | 109 | 78 | 0.4 | 0% | 0 | 1345 |
| Sep | 104 | 71 | 0.4 | 0% | 0 | 1122 |
| Oct | 91 | 57 | 0.2 | 0% | 0 | 738 |
| Nov | 78 | 47 | 0.2 | 14% | 1 | 380 |
| Dec | 66 | 38 | 0.5 | 81% | 5 | 102 |
Monthly normals 1991–2020 at Blythe, CA (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, Quartzsite, AZ, 23 miles east of Blythe and 607 feet higher, has a last frost 3 days later (January 28), a first frost 6 days earlier (December 6), a season 10 days shorter.
When it snows in Blythe, California
Measurable snow is rare here: only 0 of 22 winters from 1991 to 2020 recorded 0.1 inch or more at Blythe, CA, 1.6 miles away, so there is no typical first-snow date to plan around.
Planting calendar for 92225
| When | What to do |
|---|---|
| November 16 – November 30 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| November 30 – December 14 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| December 28 – January 11 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| January 25 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by September 19 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by November 28 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| December 12 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 92225 is 2 miles from Blythe, CA, which stands at 268 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 92225 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.