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USDA Hardiness Zone 9b

Frost Dates for 95388 — Winton, California

NOAA 1991–2020 normals from Merced, CA (154 ft), 9 miles southeast.

Updated

In Winton, the last spring frost (32°F) is around March 3 in half of years and has passed by April 10 in nine years out of ten. The first fall frost comes around November 24, as early as November 5 one year in ten, leaving a typical freeze-free season of 263 days (NOAA, Merced, CA).

Last spring frost
March 3

50% probability

First fall frost
November 24

50% probability

Growing season
263 days

freeze-free, 50%

Hardiness zone
9b

25 to 30°F (-3.9 to -1.1°C) coldest night

First snow
Rare

median, 1991–2020

Last snow
Rare

median, 1991–2020

Winters with snow
0%

0 of 20 observed

Snow per year
0"

NOAA normal

Frost risk by date in Winton

Half of springs at Merced, CA see their last 32°F night by March 3; only one in ten is past it by February 2, and one in ten still has one after April 10. Planting tender crops after March 19 leaves a 30% risk of a frost on them, after March 30 20%, and after April 10 10%. The 38 days between the even-odds date and the one-in-ten date is wider 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 24 in half of years, as early as November 5 one year in ten, and holds off past December 14 one year in ten. A hard freeze of 28°F follows 17 days later, around December 11; in spring the one-in-ten date for 28°F is March 11, 30 days before the 32°F one. The freeze-free season lasts 263 days in a typical year, shorter than at 60% of the 219 California stations; it reaches 303 days one year in ten and falls short of 226 one year in ten. On average 24 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 35 days longer, to about April 7, and return around November 8. Nights of 24°F, cold enough to damage hardier plants, come in 57% of winters and 16°F in 1%.

Spring: the chance of another night this cold after the date
Low90%80%70%60%50%40%30%20%10%
36°FMar 6Mar 17Mar 27Apr 2Apr 7Apr 11Apr 17Apr 22May 1
32°FFeb 2Feb 13Feb 22Feb 27Mar 3Mar 11Mar 19Mar 30Apr 10
28°F95% of yrsDec 28Jan 8Jan 19Jan 27Feb 2Feb 9Feb 17Feb 26Mar 11
24°F57% of yrsDec 16Dec 25Dec 30Jan 4Jan 9Jan 15Jan 22Jan 31Feb 11
20°F17% of yrstoo rare for a date
16°F1% of yrstoo rare for a date
Fall: the chance the first night this cold has come by the date
Low10%20%30%40%50%60%70%80%90%
36°FOct 21Oct 29Nov 2Nov 4Nov 8Nov 11Nov 15Nov 19Nov 24
32°FNov 5Nov 11Nov 16Nov 21Nov 24Nov 27Dec 1Dec 5Dec 14
28°F95% of yrsNov 22Nov 29Dec 2Dec 6Dec 11Dec 16Dec 24Jan 1Jan 14
24°F57% of yrsDec 2Dec 8Dec 13Dec 18Dec 24Dec 29Jan 3Jan 10Jan 24
20°F17% of yrstoo rare for a date
16°F1% of yrstoo rare for a date

Freeze probabilities 1991–2020 at Merced, 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 95388 →Compare Winton with another place →

Weather by month in Winton

July is the warmest month at Merced, CA, averaging 95°F by day and 62°F at night; December is the coldest at 55°F and 36°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 76% of years and March still brings one in 44% of years and April still brings one in 18% of years.

Warmth for growing adds up to 4,678 growing degree days a year (base 50°F), more than at 54% of the 283 California stations. 37% of them (1,725) have built up by the end of June, and July adds the most, 877. Precipitation totals 12.5 inches a year, most in January (2.7") and least in July (0.0"); May to September bring 6% of it.

Monthly normals 1991–2020 at Merced, CA
MonthHigh °FLow °FPrecip. in32°F nightNights ≤ 32°FGDD 50°F
Jan54372.794%815
Feb61392.276%453
Mar67421.944%1157
Apr73461.018%<1282
May82520.60%0521
Jun89570.10%0698
Jul95620.00%0877
Aug94600.00%0836
Sep89560.10%0681
Oct79490.76%<1424
Nov65411.266%2118
Dec55362.092%918

Monthly normals 1991–2020 at Merced, CA (154 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, Merced Municipal Airport, CA, 10 miles southeast of Winton, has a last frost 5 days earlier (February 26), a first frost 1 day later (November 25), a season 10 days longer.

Frost dates for 95340 (Merced) →

When it snows in Winton, California

Measurable snow is rare here: only 0 of 20 winters from 1991 to 2020 recorded 0.1 inch or more at Merced, CA, 9.3 miles away, so there is no typical first-snow date to plan around.

Planting calendar for 95388

What to do and when, from the 50% frost dates for Winton, California
WhenWhat to do
December 23 – January 6Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out.
January 6 – January 20Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early.
February 3 – February 17Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil.
March 3 onwardTransplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast.
by September 1Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops.
by November 10Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation.
November 24 onwardPlant 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 95388 is 9 miles from Merced, CA, which stands at 154 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 2 other ZIP codes share the station; its figures are presented in full for 95301 (Atwater). The 2023 USDA Plant Hardiness Zone Map lists ZIP 95388 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.

ZIP codes measured at the same station

Other zone 9b places in California