Frost Dates for 27278 — Hillsborough, North Carolina

Half of springs at Durham 11 W, NC see their last 32°F night by March 31; only one in ten is past it by March 14, and one in ten still has one after April 19. Planting tender crops after April 6 leaves a 30% risk of a frost on them, after April 11 20%, and after April 19 10%. The 19 days between the even-odds date and the one-in-ten date is wider than at 90% of the 173 North Carolina stations behind this site's ZIP pages.

In fall the first 32°F night comes by November 4 in half of years, as early as October 22 one year in ten, and holds off past November 18 one year in ten. A hard freeze of 28°F follows 11 days later, around November 15; in spring the one-in-ten date for 28°F is April 5, 14 days before the 32°F one. The freeze-free season lasts 217 days in a typical year, shorter than at 50% of the 173 North Carolina stations; it reaches 240 days one year in ten and falls short of 194 one year in ten. On average 71 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 15 days longer, to about April 15, and return around October 26. Nights of 24°F, cold enough to damage hardier plants, come in 100% of winters and 16°F in 83%.

July is the warmest month at Durham 11 W, NC, averaging 88°F by day and 67°F at night; January is the coldest at 50°F and 30°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 45% of years.

Warmth for growing adds up to 4,441 growing degree days a year (base 50°F), fewer than at 61% of the 173 North Carolina stations. 38% of them (1,704) have built up by the end of June, and July adds the most, 859. Precipitation totals 46.7 inches a year, most in September (5.6") and least in February (3.3"); May to September bring 46% of it.

The nearest other station, Durham, NC, 8 miles east of Hillsborough and 162 feet lower, has a last frost 2 days later (April 2), the same first-frost date.

Measurable snow is rare here: only 5 of 20 winters from 1991 to 2020 recorded 0.1 inch or more at Butner Fltr Plt, NC, 18.4 miles away, so there is no typical first-snow date to plan around.

ZIP 27278 is 8 miles from Durham 11 W, NC, which stands at 562 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 27278 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.