USDA Hardiness Zone 8a
Frost Dates for 27518 — Cary, North Carolina
NOAA 1991–2020 normals from Raleigh State Univ, NC (400 ft), 4 miles west.
Updated
In Cary, the last spring frost (32°F) is around March 28 in half of years and has passed by April 12 in nine years out of ten. The first fall frost comes around November 8, as early as October 28 one year in ten, leaving a typical freeze-free season of 229 days (NOAA, Raleigh State Univ, NC).
- Last spring frost
- March 28
- First fall frost
- November 8
- Growing season
- 229 days
- Hardiness zone
- 8a
50% probability
50% probability
freeze-free, 50%
10 to 15°F (-12.2 to -9.4°C) coldest night
- First snow
- Rare
- Last snow
- Rare
- Winters with snow
- 35%
- Snow per year
- —
median, 1991–2020
median, 1991–2020
7 of 20 observed
NOAA normal
Frost risk by date in Cary
Half of springs at Raleigh State Univ, NC see their last 32°F night by March 28; only one in ten is past it by March 8, and one in ten still has one after April 12. Planting tender crops after April 3 leaves a 30% risk of a frost on them, after April 7 20%, and after April 12 10%. The 15 days between the even-odds date and the one-in-ten date is narrower than at 57% of the 173 North Carolina stations behind this site's ZIP pages.
In fall the first 32°F night comes by November 8 in half of years, as early as October 28 one year in ten, and holds off past November 27 one year in ten. A hard freeze of 28°F follows 15 days later, around November 23; in spring the one-in-ten date for 28°F is March 31, 12 days before the 32°F one. The freeze-free season lasts 229 days in a typical year, longer than at 78% of the 173 North Carolina stations; it reaches 255 days one year in ten and falls short of 208 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 10 days longer, to about April 7, and return around October 31. Nights of 24°F, cold enough to damage hardier plants, come in 100% of winters and 16°F in 69%.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Mar 25 | Mar 30 | Apr 2 | Apr 5 | Apr 7 | Apr 10 | Apr 13 | Apr 16 | Apr 21 |
| 32°F | Mar 8 | Mar 16 | Mar 20 | Mar 24 | Mar 28 | Apr 1 | Apr 3 | Apr 7 | Apr 12 |
| 28°F | Feb 22 | Feb 28 | Mar 5 | Mar 9 | Mar 14 | Mar 17 | Mar 20 | Mar 25 | Mar 31 |
| 24°F | Feb 2 | Feb 11 | Feb 18 | Feb 24 | Feb 28 | Mar 3 | Mar 7 | Mar 11 | Mar 19 |
| 20°F95% of yrs | Jan 13 | Jan 23 | Jan 31 | Feb 3 | Feb 9 | Feb 15 | Feb 23 | Feb 28 | Mar 7 |
| 16°F69% of yrs | Jan 5 | Jan 12 | Jan 17 | Jan 23 | Jan 28 | Jan 31 | Feb 5 | Feb 14 | Feb 25 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 18 | Oct 23 | Oct 26 | Oct 29 | Oct 31 | Nov 2 | Nov 5 | Nov 8 | Nov 14 |
| 32°F | Oct 28 | Nov 1 | Nov 4 | Nov 6 | Nov 8 | Nov 12 | Nov 16 | Nov 20 | Nov 27 |
| 28°F | Nov 6 | Nov 11 | Nov 15 | Nov 19 | Nov 23 | Nov 27 | Dec 1 | Dec 6 | Dec 15 |
| 24°F | Nov 18 | Nov 26 | Dec 1 | Dec 5 | Dec 10 | Dec 17 | Dec 23 | Dec 31 | Jan 7 |
| 20°F95% of yrs | Dec 4 | Dec 12 | Dec 19 | Dec 26 | Jan 1 | Jan 5 | Jan 10 | Jan 16 | Jan 26 |
| 16°F69% of yrs | Dec 23 | Jan 1 | Jan 4 | Jan 8 | Jan 12 | Jan 16 | Jan 22 | Jan 27 | Feb 5 |
Freeze probabilities 1991–2020 at Raleigh State Univ, 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 27518 →Compare Cary with another place →
Weather by month in Cary
July is the warmest month at Raleigh State Univ, NC, averaging 91°F by day and 70°F at night; January is the coldest at 52°F and 32°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 40% of years.
Warmth for growing adds up to 4,990 growing degree days a year (base 50°F), more than at 67% of the 173 North Carolina stations. 39% of them (1,930) have built up by the end of June, and July adds the most, 944. Precipitation totals 49.5 inches a year, most in September (5.7") and least in February (2.9"); May to September bring 48% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 52 | 32 | 3.7 | 100% | 18 | 34 |
| Feb | 55 | 33 | 2.9 | 100% | 14 | 39 |
| Mar | 63 | 40 | 4.2 | 93% | 7 | 138 |
| Apr | 72 | 49 | 3.6 | 40% | 1 | 329 |
| May | 80 | 58 | 4.0 | 0% | 0 | 591 |
| Jun | 87 | 66 | 4.9 | 0% | 0 | 799 |
| Jul | 91 | 70 | 4.7 | 0% | 0 | 944 |
| Aug | 89 | 69 | 4.7 | 0% | 0 | 891 |
| Sep | 82 | 63 | 5.7 | 0% | 0 | 679 |
| Oct | 73 | 51 | 3.9 | 19% | <1 | 370 |
| Nov | 62 | 41 | 3.5 | 93% | 5 | 126 |
| Dec | 55 | 35 | 3.7 | 98% | 13 | 50 |
Monthly normals 1991–2020 at Raleigh State Univ, NC (400 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, Raleigh 4 SW, NC, 6 miles southwest of Cary, has the same 50% last-frost date, a first frost 1 day later (November 9), a season 2 days shorter.
When it snows in Cary, North Carolina
Measurable snow is rare here: only 7 of 20 winters from 1991 to 2020 recorded 0.1 inch or more at Raleigh 4 SW, NC, 5.8 miles away, so there is no typical first-snow date to plan around.
Planting calendar for 27518
| When | What to do |
|---|---|
| January 17 – January 31 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| January 31 – February 14 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| February 28 – March 14 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| March 28 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by August 16 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 25 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| November 8 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 27518 is 4 miles from Raleigh State Univ, NC, which stands at 400 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 10 other ZIP codes share the station; its figures are presented in full for 27616 (Raleigh). The 2023 USDA Plant Hardiness Zone Map lists ZIP 27518 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 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.