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USDA Hardiness Zone 8a

Frost Dates for 29672 — Seneca, South Carolina

NOAA 1991–2020 normals from Clemson Oconee Co Airport, SC (891 ft), 6 miles southeast.

Updated

In Seneca, the last spring frost (32°F) is around March 21 in half of years and has passed by April 7 in nine years out of ten. The first fall frost comes around November 11, as early as October 28 one year in ten, leaving a typical freeze-free season of 236 days (NOAA, Clemson Oconee Co Airport, SC).

Last spring frost
March 21

50% probability

First fall frost
November 11

50% probability

Growing season
236 days

freeze-free, 50%

Hardiness zone
8a

10 to 15°F (-12.2 to -9.4°C) coldest night

First snow
Rare

median, 1991–2020

Last snow
Rare

median, 1991–2020

Winters with snow
23%

5 of 22 observed

Snow per year
1"

NOAA normal

Frost risk by date in Seneca

Half of springs at Clemson Oconee Co Airport, SC see their last 32°F night by March 21; only one in ten is past it by March 1, and one in ten still has one after April 7. Planting tender crops after March 28 leaves a 30% risk of a frost on them, after April 1 20%, and after April 7 10%. The 17 days between the even-odds date and the one-in-ten date is wider than at 57% of the 105 South Carolina stations behind this site's ZIP pages.

In fall the first 32°F night comes by November 11 in half of years, as early as October 28 one year in ten, and holds off past December 1 one year in ten. A hard freeze of 28°F follows 16 days later, around November 27; in spring the one-in-ten date for 28°F is March 24, 14 days before the 32°F one. The freeze-free season lasts 236 days in a typical year, longer than at 62% of the 105 South Carolina stations; it reaches 263 days one year in ten and falls short of 212 one year in ten. On average 38 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 13 days longer, to about April 3, and return around November 1. Nights of 24°F, cold enough to damage hardier plants, come in 100% of winters and 16°F in 59%.

Spring: the chance of another night this cold after the date
Low90%80%70%60%50%40%30%20%10%
36°FMar 18Mar 24Mar 28Apr 1Apr 3Apr 6Apr 10Apr 14Apr 19
32°FMar 1Mar 8Mar 14Mar 18Mar 21Mar 25Mar 28Apr 1Apr 7
28°FFeb 10Feb 20Feb 26Mar 2Mar 7Mar 11Mar 15Mar 18Mar 24
24°FJan 19Jan 30Feb 5Feb 13Feb 19Feb 24Mar 1Mar 7Mar 15
20°F88% of yrsJan 4Jan 14Jan 21Jan 27Jan 31Feb 6Feb 13Feb 22Mar 4
16°F59% of yrsDec 31Jan 7Jan 14Jan 18Jan 24Jan 29Feb 1Feb 7Feb 18
Fall: the chance the first night this cold has come by the date
Low10%20%30%40%50%60%70%80%90%
36°FOct 19Oct 24Oct 27Oct 30Nov 1Nov 4Nov 6Nov 10Nov 15
32°FOct 28Nov 2Nov 5Nov 8Nov 11Nov 15Nov 19Nov 24Dec 1
28°FNov 8Nov 13Nov 18Nov 22Nov 27Dec 1Dec 5Dec 10Dec 21
24°FNov 21Nov 29Dec 4Dec 8Dec 14Dec 23Dec 29Jan 3Jan 13
20°F88% of yrsDec 7Dec 15Dec 24Dec 29Jan 2Jan 7Jan 13Jan 19Jan 30
16°F59% of yrsDec 21Dec 30Jan 2Jan 6Jan 12Jan 16Jan 20Jan 28Feb 5

Freeze probabilities 1991–2020 at Clemson Oconee Co Airport, SC, 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 29672 →Compare Seneca with another place →

Weather by month in Seneca

July is the warmest month at Clemson Oconee Co Airport, SC, averaging 89°F by day and 70°F at night; January is the coldest at 52°F and 34°F. A freezing night is all but certain in every month from December to February (a 90% chance or more). From May to September the chance of a 32°F night stays under 10% each month. In spring, March still brings one in 88% of years and April still brings one in 22% of years.

Warmth for growing adds up to 4,946 growing degree days a year (base 50°F), fewer than at 80% of the 105 South Carolina stations. 39% of them (1,931) have built up by the end of June, and July adds the most, 908. Precipitation totals 49.1 inches a year, most in August (4.9") and least in May (3.5"); May to September bring 41% of it.

Monthly normals 1991–2020 at Clemson Oconee Co Airport, SC
MonthHigh °FLow °FPrecip. in32°F nightNights ≤ 32°FGDD 50°F
Jan52344.5100%1432
Feb56364.298%849
Mar64434.788%3164
Apr72503.822%<1335
May79593.50%0581
Jun85664.40%0770
Jul89703.70%0908
Aug87694.90%0870
Sep82643.70%0682
Oct72523.617%<1379
Nov62423.687%3127
Dec54364.599%1048

Monthly normals 1991–2020 at Clemson Oconee Co Airport, SC (891 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, Walhalla, SC, 7 miles west of Seneca, has a last frost 21 days later (April 11), a first frost 12 days earlier (October 30), a season 33 days shorter.

Frost dates for 29693 (Westminster) →

When it snows in Seneca, South Carolina

Measurable snow is rare here: only 5 of 22 winters from 1991 to 2020 recorded 0.1 inch or more at Pickens, SC, 16.3 miles away, so there is no typical first-snow date to plan around.

Planting calendar for 29672

What to do and when, from the 50% frost dates for Seneca, South Carolina
WhenWhat to do
January 10 – January 24Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out.
January 24 – February 7Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early.
February 21 – March 7Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil.
March 21 onwardTransplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast.
by August 19Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops.
by October 28Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation.
November 11 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 29672 is 6 miles from Clemson Oconee Co Airport, SC, which stands at 891 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station; its figures are presented in full for 29678 (Seneca). The 2023 USDA Plant Hardiness Zone Map lists ZIP 29672 in zone 8a, the band where the coldest night of the year averaged 10 to 15°F (-12.2 to -9.4°C) over 1991–2020; a zone describes winter lows, not frost dates.

Frost dates across South Carolina →

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 8a places in South Carolina