Frost Dates for 29631 — Clemson, South Carolina

Half of springs at Clemson Univ, SC see their last 32°F night by April 1; only one in ten is past it by March 16, and one in ten still has one after April 18. Planting tender crops after April 7 leaves a 30% risk of a frost on them, after April 11 20%, and after April 18 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 3 in half of years, as early as October 21 one year in ten, and holds off past November 17 one year in ten. A hard freeze of 28°F follows 10 days later, around November 13; in spring the one-in-ten date for 28°F is April 6, 12 days before the 32°F one. The freeze-free season lasts 217 days in a typical year, shorter than at 82% of the 105 South Carolina stations; it reaches 239 days one year in ten and falls short of 197 one year in ten. On average 57 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 14, and return around October 25. Nights of 24°F, cold enough to damage hardier plants, come in 100% of winters and 16°F in 80%.

July is the warmest month at Clemson Univ, SC, averaging 91°F by day and 69°F at night; January is the coldest at 53°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 52% of years.

Warmth for growing adds up to 5,008 growing degree days a year (base 50°F), fewer than at 75% of the 105 South Carolina stations. 39% of them (1,950) have built up by the end of June, and July adds the most, 922. Precipitation totals 52.6 inches a year, most in August (5.3") and least in September (3.8"); May to September bring 41% of it.

The nearest other station, Clemson Oconee Co Airport, SC, 4 miles west of Clemson, has a last frost 11 days earlier (March 21), a first frost 8 days later (November 11), a season 19 days longer.

The first measurable snow (0.1 inch or more) in Clemson usually arrives around January 20, and the last of the season around January 24. Those are the middle dates across the winters of 1991–2020 at Clemson Univ, SC, 1.5 miles away: half of years saw snow earlier, half later. Snow fell in 79% of those winters. The last 32°F night of spring typically comes 67 days after the last snow.

ZIP 29631 is 2 miles from Clemson Univ, SC, which stands at 800 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 29631 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.