USDA Hardiness Zone 7a
Frost Dates for 28698 — Zionville, North Carolina
NOAA 1991–2020 normals from Boone 1 SE, NC (3,100 ft), 9 miles southeast.
Updated
In Zionville, the last spring frost (32°F) is around May 2 in half of years and has passed by May 19 in nine years out of ten. The first fall frost comes around October 13, as early as September 30 one year in ten, leaving a typical freeze-free season of 163 days (NOAA, Boone 1 SE, NC).
- Last spring frost
- May 2
- First fall frost
- October 13
- Growing season
- 163 days
- Hardiness zone
- 7a
50% probability
50% probability
freeze-free, 50%
0 to 5°F (-17.8 to -15.0°C) coldest night
- First snow
- December 6
- Last snow
- March 25
- Winters with snow
- 100%
- Snow per year
- 25.6"
median, 1991–2020
median, 1991–2020
30 of 30 observed
NOAA normal
Frost risk by date in Zionville
Half of springs at Boone 1 SE, NC see their last 32°F night by May 2; only one in ten is past it by April 17, and one in ten still has one after May 19. Planting tender crops after May 10 leaves a 30% risk of a frost on them, after May 14 20%, and after May 19 10%. The 17 days between the even-odds date and the one-in-ten date is wider than at 65% of the 173 North Carolina stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 13 in half of years, as early as September 30 one year in ten, and holds off past October 27 one year in ten. A hard freeze of 28°F follows 11 days later, around October 24; in spring the one-in-ten date for 28°F is May 8, 11 days before the 32°F one. The freeze-free season lasts 163 days in a typical year, shorter than at 98% of the 173 North Carolina stations; it reaches 183 days one year in ten and falls short of 141 one year in ten. On average 127 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 12 days longer, to about May 14, and return around October 3. Severe cold of 16°F or below comes every winter, usually between December 1 and March 9.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 29 | May 3 | May 7 | May 10 | May 14 | May 16 | May 20 | May 24 | May 28 |
| 32°F | Apr 17 | Apr 22 | Apr 26 | Apr 30 | May 2 | May 6 | May 10 | May 14 | May 19 |
| 28°F | Apr 2 | Apr 8 | Apr 12 | Apr 15 | Apr 19 | Apr 22 | Apr 26 | May 1 | May 8 |
| 24°F | Mar 17 | Mar 23 | Mar 28 | Mar 31 | Apr 3 | Apr 6 | Apr 9 | Apr 13 | Apr 19 |
| 20°F | Mar 3 | Mar 11 | Mar 15 | Mar 19 | Mar 22 | Mar 26 | Mar 31 | Apr 2 | Apr 7 |
| 16°F | Feb 13 | Feb 23 | Mar 1 | Mar 5 | Mar 9 | Mar 14 | Mar 17 | Mar 22 | Mar 28 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 19 | Sep 23 | Sep 27 | Sep 30 | Oct 3 | Oct 5 | Oct 8 | Oct 11 | Oct 15 |
| 32°F | Sep 30 | Oct 4 | Oct 8 | Oct 10 | Oct 13 | Oct 15 | Oct 18 | Oct 22 | Oct 27 |
| 28°F | Oct 10 | Oct 15 | Oct 18 | Oct 21 | Oct 24 | Oct 26 | Oct 29 | Nov 1 | Nov 5 |
| 24°F | Oct 21 | Oct 25 | Oct 29 | Nov 1 | Nov 3 | Nov 5 | Nov 8 | Nov 12 | Nov 18 |
| 20°F | Oct 31 | Nov 4 | Nov 7 | Nov 12 | Nov 15 | Nov 18 | Nov 23 | Nov 29 | Dec 4 |
| 16°F | Nov 10 | Nov 16 | Nov 21 | Nov 26 | Dec 1 | Dec 3 | Dec 7 | Dec 15 | Dec 24 |
Freeze probabilities 1991–2020 at Boone 1 SE, NC, 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 28698 →Compare Zionville with another place →
Weather by month in Zionville
July is the warmest month at Boone 1 SE, NC, averaging 79°F by day and 58°F at night; January is the coldest at 41°F and 22°F. A freezing night is all but certain in every month from October to April (a 90% chance or more). From June to August the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 56% of years.
Warmth for growing adds up to 2,401 growing degree days a year (base 50°F), fewer than at 97% of the 173 North Carolina stations. 34% of them (822) have built up by the end of June, and July adds the most, 569. Precipitation totals 59.1 inches a year, most in September (5.7") and least in February (3.6"); May to September bring 47% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 41 | 22 | 4.4 | 100% | 25 | 2 |
| Feb | 45 | 24 | 3.6 | 100% | 23 | 4 |
| Mar | 52 | 29 | 4.8 | 100% | 19 | 22 |
| Apr | 62 | 37 | 5.5 | 100% | 9 | 95 |
| May | 69 | 46 | 5.5 | 56% | 2 | 257 |
| Jun | 76 | 54 | 5.6 | 0% | 0 | 443 |
| Jul | 79 | 58 | 5.1 | 0% | 0 | 569 |
| Aug | 78 | 56 | 5.6 | 0% | 0 | 529 |
| Sep | 72 | 50 | 5.7 | 11% | <1 | 341 |
| Oct | 63 | 39 | 4.7 | 94% | 6 | 113 |
| Nov | 53 | 30 | 4.4 | 100% | 20 | 22 |
| Dec | 45 | 25 | 4.2 | 100% | 24 | 6 |
Monthly normals 1991–2020 at Boone 1 SE, NC (3,100 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, Flat Springs 1E, NC, 11 miles southwest of Zionville and 230 feet higher, has a last frost 14 days earlier (April 18), a first frost 11 days later (October 24), a season 25 days longer.
When it snows in Zionville, North Carolina
The first measurable snow (0.1 inch or more) in Zionville usually arrives around December 6, and the last of the season around March 25. Those are the middle dates across the winters of 1991–2020 at Boone 1 SE, NC, 9.2 miles away: half of years saw snow earlier, half later. Every one of those winters saw snow. The last 32°F night of spring typically comes 38 days after the last snow.
Planting calendar for 28698
| When | What to do |
|---|---|
| February 21 – March 7 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 7 – March 21 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 4 – April 18 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| May 2 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 21 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 29 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 13 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 28698 is 9 miles from Boone 1 SE, NC, which stands at 3,100 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 3 other ZIP codes share the station; its figures are presented in full for 28607 (Boone). The 2023 USDA Plant Hardiness Zone Map lists ZIP 28698 in zone 7a, the band where the coldest night of the year averaged 0 to 5°F (-17.8 to -15.0°C) over 1991–2020; a zone describes winter lows, not frost dates.
Frost dates across North 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.