USDA Hardiness Zone 9b
Frost Dates for 95220 — Acampo, California
NOAA 1991–2020 normals from Lodi, CA (40 ft), 7 miles southwest.
Updated
In Acampo, the last spring frost (32°F) is around February 9 in half of years and has passed by March 7 in nine years out of ten. The first fall frost comes around December 5, as early as November 17 one year in ten, leaving a typical freeze-free season of 301 days (NOAA, Lodi, CA).
- Last spring frost
- February 9
- First fall frost
- December 5
- Growing season
- 301 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
- 5%
- Snow per year
- 0"
median, 1991–2020
median, 1991–2020
1 of 20 observed
NOAA normal
Frost risk by date in Acampo
Half of springs at Lodi, CA see their last 32°F night by February 9; only one in ten is past it by January 2, and one in ten still has one after March 7. Planting tender crops after February 22 leaves a 30% risk of a frost on them, after February 28 20%, and after March 7 10%. The 26 days between the even-odds date and the one-in-ten date is narrower than at 67% 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 5 in half of years, as early as November 17 one year in ten, and holds off past January 3 one year in ten. A hard freeze of 28°F follows 15 days later, around December 20; in spring the one-in-ten date for 28°F is February 18, 17 days before the 32°F one. The freeze-free season lasts 301 days in a typical year, longer than at 64% of the 219 California stations; it reaches 339 days one year in ten and falls short of 264 one year in ten. On average 20 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 30 days longer, to about March 11, and return around November 19. A 24°F night is unusual: 23% of winters had one.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Feb 9 | Feb 21 | Feb 27 | Mar 4 | Mar 11 | Mar 18 | Mar 26 | Apr 5 | Apr 20 |
| 32°F98% of yrs | Jan 2 | Jan 15 | Jan 26 | Feb 2 | Feb 9 | Feb 15 | Feb 22 | Feb 28 | Mar 7 |
| 28°F73% of yrs | Dec 12 | Dec 26 | Dec 31 | Jan 5 | Jan 12 | Jan 19 | Jan 29 | Feb 6 | Feb 18 |
| 24°F23% of yrs | too rare for a date | ||||||||
| 20°F1% of yrs | too rare for a date | ||||||||
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Nov 5 | Nov 9 | Nov 14 | Nov 17 | Nov 19 | Nov 22 | Nov 25 | Nov 29 | Dec 4 |
| 32°F98% of yrs | Nov 17 | Nov 24 | Nov 29 | Dec 1 | Dec 5 | Dec 9 | Dec 14 | Dec 21 | Jan 3 |
| 28°F73% of yrs | Nov 30 | Dec 5 | Dec 10 | Dec 14 | Dec 20 | Dec 27 | Jan 1 | Jan 6 | Jan 24 |
| 24°F23% of yrs | too rare for a date | ||||||||
| 20°F1% of yrs | too rare for a date | ||||||||
Freeze probabilities 1991–2020 at Lodi, 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 95220 →Compare Acampo with another place →
Weather by month in Acampo
July is the warmest month at Lodi, CA, averaging 92°F by day and 59°F at night; December is the coldest at 57°F and 39°F. From April to October the chance of a 32°F night stays under 10% each month. In spring, February still brings one in 54% of years and March still brings one in 15% of years.
Warmth for growing adds up to 4,747 growing degree days a year (base 50°F), more than at 56% of the 283 California stations. 39% of them (1,855) have built up by the end of June, and July adds the most, 798. Precipitation totals 18.2 inches a year, most in December (3.6") and least in July (0.0"); May to September bring 5% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 57 | 40 | 3.5 | 77% | 6 | 36 |
| Feb | 63 | 42 | 3.4 | 54% | 3 | 87 |
| Mar | 69 | 45 | 2.5 | 15% | <1 | 215 |
| Apr | 74 | 47 | 1.5 | 1% | <1 | 320 |
| May | 81 | 52 | 0.7 | 2% | 0 | 521 |
| Jun | 88 | 57 | 0.2 | 0% | 0 | 675 |
| Jul | 92 | 59 | 0.0 | 0% | 0 | 798 |
| Aug | 92 | 58 | 0.0 | 0% | 0 | 777 |
| Sep | 89 | 56 | 0.1 | 0% | 0 | 671 |
| Oct | 79 | 50 | 0.9 | 0% | 0 | 460 |
| Nov | 65 | 43 | 1.8 | 33% | 2 | 152 |
| Dec | 57 | 39 | 3.6 | 79% | 8 | 34 |
Monthly normals 1991–2020 at Lodi, CA (40 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, Stockton Fire Stn 4, CA, 15 miles south of Acampo, has a last frost 4 days earlier (February 5), a first frost 3 days later (December 8), a season 4 days longer.
When it snows in Acampo, California
Measurable snow is rare here: only 1 of 20 winters from 1991 to 2020 recorded 0.1 inch or more at Acampo 5NE, CA, 2.2 miles away, so there is no typical first-snow date to plan around.
Planting calendar for 95220
| When | What to do |
|---|---|
| December 1 – December 15 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| December 15 – December 29 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| January 12 – January 26 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| February 9 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by September 12 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by November 21 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| December 5 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 95220 is 7 miles from Lodi, CA, which stands at 40 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 95240 (Lodi). The 2023 USDA Plant Hardiness Zone Map lists ZIP 95220 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.