USDA Hardiness Zone 8b
Frost Dates for 95311 — Coulterville, California
NOAA 1991–2020 normals from Groveland 2, CA (2,800 ft), 8 miles northwest.
Updated
In Coulterville, the last spring frost (32°F) is around April 22 in half of years and has passed by May 14 in nine years out of ten. The first fall frost comes around November 2, as early as October 13 one year in ten, leaving a typical freeze-free season of 192 days (NOAA, Groveland 2, CA).
- Last spring frost
- April 22
- First fall frost
- November 2
- Growing season
- 192 days
- Hardiness zone
- 8b
50% probability
50% probability
freeze-free, 50%
15 to 20°F (-9.4 to -6.7°C) coldest night
- First snow
- Rare
- Last snow
- Rare
- Winters with snow
- 40%
- Snow per year
- 3.8"
median, 1991–2020
median, 1991–2020
6 of 15 observed
NOAA normal
Frost risk by date in Coulterville
Half of springs at Groveland 2, CA see their last 32°F night by April 22; only one in ten is past it by April 5, and one in ten still has one after May 14. Planting tender crops after May 1 leaves a 30% risk of a frost on them, after May 7 20%, and after May 14 10%. The 22 days between the even-odds date and the one-in-ten date is narrower than at 81% 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 2 in half of years, as early as October 13 one year in ten, and holds off past November 20 one year in ten. A hard freeze of 28°F follows 17 days later, around November 19; in spring the one-in-ten date for 28°F is April 22, 22 days before the 32°F one. The freeze-free season lasts 192 days in a typical year, shorter than at 83% of the 219 California stations; it reaches 220 days one year in ten and falls short of 163 one year in ten. On average 91 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 19 days longer, to about May 11, and return around October 14. Nights of 24°F, cold enough to damage hardier plants, come in 100% of winters and 16°F in 35%.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 25 | Apr 30 | May 4 | May 8 | May 11 | May 14 | May 18 | May 25 | May 30 |
| 32°F | Apr 5 | Apr 9 | Apr 14 | Apr 18 | Apr 22 | Apr 27 | May 1 | May 7 | May 14 |
| 28°F | Mar 5 | Mar 13 | Mar 19 | Mar 25 | Mar 29 | Apr 2 | Apr 7 | Apr 13 | Apr 22 |
| 24°F | Jan 20 | Feb 4 | Feb 12 | Feb 21 | Feb 27 | Mar 3 | Mar 9 | Mar 15 | Mar 25 |
| 20°F85% of yrs | Dec 20 | Dec 31 | Jan 5 | Jan 14 | Jan 23 | Feb 3 | Feb 10 | Feb 21 | Mar 1 |
| 16°F35% of yrs | too rare for a date | ||||||||
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 27 | Oct 1 | Oct 6 | Oct 11 | Oct 14 | Oct 18 | Oct 22 | Oct 28 | Nov 2 |
| 32°F | Oct 13 | Oct 20 | Oct 26 | Oct 30 | Nov 2 | Nov 5 | Nov 8 | Nov 13 | Nov 20 |
| 28°F | Oct 30 | Nov 5 | Nov 9 | Nov 14 | Nov 19 | Nov 23 | Nov 26 | Dec 1 | Dec 7 |
| 24°F | Nov 15 | Nov 21 | Nov 26 | Dec 1 | Dec 4 | Dec 9 | Dec 14 | Dec 19 | Dec 29 |
| 20°F85% of yrs | Nov 29 | Dec 6 | Dec 14 | Dec 19 | Dec 25 | Dec 29 | Jan 3 | Jan 14 | Jan 31 |
| 16°F35% of yrs | too rare for a date | ||||||||
Freeze probabilities 1991–2020 at Groveland 2, 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 95311 →Compare Coulterville with another place →
Weather by month in Coulterville
July is the warmest month at Groveland 2, CA, averaging 91°F by day and 56°F at night; December is the coldest at 52°F and 31°F. A freezing night is all but certain in every month from November to April (a 90% chance or more). From June to September the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 33% of years.
Warmth for growing adds up to 3,242 growing degree days a year (base 50°F), fewer than at 78% of the 283 California stations. 30% of them (970) have built up by the end of June, and July adds the most, 736. Precipitation totals 38.6 inches a year, most in January (7.2") and least in July (0.0"); May to September bring 8% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 53 | 31 | 7.2 | 100% | 20 | 6 |
| Feb | 55 | 32 | 6.9 | 100% | 16 | 12 |
| Mar | 60 | 35 | 6.3 | 99% | 12 | 50 |
| Apr | 65 | 38 | 3.0 | 93% | 7 | 110 |
| May | 73 | 44 | 2.2 | 33% | 1 | 281 |
| Jun | 83 | 51 | 0.4 | 0% | 0 | 512 |
| Jul | 91 | 56 | 0.0 | 0% | 0 | 736 |
| Aug | 91 | 55 | 0.1 | 0% | 0 | 707 |
| Sep | 85 | 50 | 0.3 | 2% | <1 | 520 |
| Oct | 74 | 42 | 2.1 | 43% | 2 | 253 |
| Nov | 60 | 35 | 3.5 | 98% | 12 | 52 |
| Dec | 52 | 31 | 6.6 | 100% | 20 | 4 |
Monthly normals 1991–2020 at Groveland 2, CA (2,800 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, Sonora, CA, 20 miles northwest of Coulterville and 1,125 feet lower, has a last frost 13 days earlier (April 9), a first frost 7 days later (November 9), a season 21 days longer.
When it snows in Coulterville, California
Measurable snow is rare here: only 6 of 15 winters from 1991 to 2020 recorded 0.1 inch or more at Groveland 2, CA, 7.9 miles away, so there is no typical first-snow date to plan around.
Planting calendar for 95311
| When | What to do |
|---|---|
| February 11 – February 25 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 25 – March 11 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 25 – April 8 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 22 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by August 10 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 19 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| November 2 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 95311 is 8 miles from Groveland 2, CA, which stands at 2,800 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 3 other ZIP codes share the station; its figures are presented in full for 95321 (Groveland). The 2023 USDA Plant Hardiness Zone Map lists ZIP 95311 in zone 8b, the band where the coldest night of the year averaged 15 to 20°F (-9.4 to -6.7°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.