USDA Hardiness Zone 9a
Frost Dates for 95458 — Lucerne, California
NOAA 1991–2020 normals from Clearlake 4 SE, CA (1,349 ft), 17 miles southeast.
Updated
In Lucerne, the last spring frost (32°F) is around April 10 in half of years and has passed by April 30 in nine years out of ten. The first fall frost comes around November 6, as early as October 24 one year in ten, leaving a typical freeze-free season of 209 days (NOAA, Clearlake 4 SE, CA).
- Last spring frost
- April 10
- First fall frost
- November 6
- Growing season
- 209 days
- Hardiness zone
- 9a
50% probability
50% probability
freeze-free, 50%
20 to 25°F (-6.7 to -3.9°C) coldest night
- First snow
- Rare
- Last snow
- Rare
- Winters with snow
- 28%
- Snow per year
- 0.4"
median, 1991–2020
median, 1991–2020
5 of 18 observed
NOAA normal
Frost risk by date in Lucerne
Half of springs at Clearlake 4 SE, CA see their last 32°F night by April 10; only one in ten is past it by March 24, and one in ten still has one after April 30. Planting tender crops after April 18 leaves a 30% risk of a frost on them, after April 23 20%, and after April 30 10%. The 20 days between the even-odds date and the one-in-ten date is narrower than at 88% of the 220 California stations behind this site's ZIP pages.
In fall the first 32°F night comes by November 6 in half of years, as early as October 24 one year in ten, and holds off past November 20 one year in ten. A hard freeze of 28°F follows 15 days later, around November 21; in spring the one-in-ten date for 28°F is April 7, 23 days before the 32°F one. The freeze-free season lasts 209 days in a typical year, shorter than at 79% of the 219 California stations; it reaches 231 days one year in ten and falls short of 186 one year in ten. On average 72 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 20 days longer, to about April 30, and return around October 27. Nights of 24°F, cold enough to damage hardier plants, come in 96% of winters and 16°F in 16%.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 14 | Apr 20 | Apr 24 | Apr 27 | Apr 30 | May 2 | May 6 | May 10 | May 16 |
| 32°F | Mar 24 | Mar 31 | Apr 4 | Apr 7 | Apr 10 | Apr 14 | Apr 18 | Apr 23 | Apr 30 |
| 28°F | Feb 12 | Feb 25 | Mar 2 | Mar 9 | Mar 14 | Mar 21 | Mar 27 | Mar 31 | Apr 7 |
| 24°F96% of yrs | Dec 29 | Jan 11 | Jan 22 | Jan 30 | Feb 7 | Feb 15 | Feb 23 | Feb 28 | Mar 8 |
| 20°F58% of yrs | Dec 11 | Dec 21 | Dec 29 | Jan 4 | Jan 11 | Jan 20 | Jan 26 | Feb 1 | Feb 14 |
| 16°F16% of yrs | too rare for a date | ||||||||
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 11 | Oct 17 | Oct 21 | Oct 24 | Oct 27 | Oct 29 | Nov 1 | Nov 3 | Nov 7 |
| 32°F | Oct 24 | Oct 29 | Nov 1 | Nov 4 | Nov 6 | Nov 9 | Nov 11 | Nov 14 | Nov 20 |
| 28°F | Nov 4 | Nov 10 | Nov 13 | Nov 17 | Nov 21 | Nov 24 | Nov 28 | Dec 1 | Dec 8 |
| 24°F96% of yrs | Nov 17 | Nov 25 | Dec 1 | Dec 3 | Dec 6 | Dec 11 | Dec 18 | Dec 29 | Jan 11 |
| 20°F58% of yrs | Dec 1 | Dec 6 | Dec 11 | Dec 17 | Dec 22 | Dec 30 | Jan 4 | Jan 14 | Jan 30 |
| 16°F16% of yrs | too rare for a date | ||||||||
Freeze probabilities 1991–2020 at Clearlake 4 SE, 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 95458 →Compare Lucerne with another place →
Weather by month in Lucerne
July is the warmest month at Clearlake 4 SE, CA, averaging 91°F by day and 56°F at night; January is the coldest at 55°F and 33°F. A freezing night is all but certain in every month from November to March (a 90% chance or more). From May to September the chance of a 32°F night stays under 10% each month. In spring, April still brings one in 76% of years.
Warmth for growing adds up to 3,335 growing degree days a year (base 50°F), fewer than at 76% of the 283 California stations. 30% of them (1,009) have built up by the end of June, and July adds the most, 733. Precipitation totals 30.0 inches a year, most in January (6.2") and least in July (0.0"); May to September bring 6% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 55 | 33 | 6.2 | 97% | 18 | 6 |
| Feb | 58 | 34 | 6.2 | 98% | 13 | 19 |
| Mar | 62 | 35 | 4.0 | 97% | 9 | 57 |
| Apr | 66 | 39 | 2.0 | 76% | 3 | 124 |
| May | 73 | 45 | 1.2 | 9% | <1 | 281 |
| Jun | 83 | 52 | 0.2 | 0% | 0 | 521 |
| Jul | 91 | 56 | 0.0 | 0% | 0 | 733 |
| Aug | 91 | 54 | 0.1 | 0% | 0 | 694 |
| Sep | 85 | 50 | 0.2 | 0% | 0 | 536 |
| Oct | 75 | 43 | 0.9 | 26% | 1 | 294 |
| Nov | 63 | 36 | 2.9 | 99% | 11 | 62 |
| Dec | 55 | 33 | 6.1 | 99% | 18 | 7 |
Monthly normals 1991–2020 at Clearlake 4 SE, CA (1,349 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, Ukiah Municipal Airport, CA, 22 miles west of Lucerne and 748 feet lower, has a last frost 36 days earlier (March 5), a first frost 15 days later (November 21), a season 50 days longer.
When it snows in Lucerne, California
Measurable snow is rare here: only 5 of 18 winters from 1991 to 2020 recorded 0.1 inch or more at Clearlake 4 SE, CA, 16.6 miles away, so there is no typical first-snow date to plan around.
Planting calendar for 95458
| When | What to do |
|---|---|
| January 30 – February 13 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 13 – February 27 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 13 – March 27 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 10 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by August 14 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 23 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| November 6 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 95458 is 17 miles from Clearlake 4 SE, CA, which stands at 1,349 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 6 other ZIP codes share the station; its figures are presented in full for 95422 (Clearlake). The 2023 USDA Plant Hardiness Zone Map lists ZIP 95458 in zone 9a, the band where the coldest night of the year averaged 20 to 25°F (-6.7 to -3.9°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.