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Frost dates and planting calendar for Wilmington, North Carolina

Updated October 30, 2026. Based on USDA, NOAA and Colorado State University Extension data. Published by Humblebee.

USDA hardiness zone
8b[1]
Median last spring frost
Mar 19[2]
Median first fall frost
Nov 20[3]
Growing season, median
247 days[4]

Wilmington, North Carolina is in USDA hardiness zone 8b[1]. The median last spring frost is March 19, which means that in half of years the last frost comes after that date[2].

Frost dates

JanFebMarAprMayJunJulAugSepOctNovDecLast spring frost: 9 in 10 years after Feb 26, half of years Mar 19, 1 in 10 years after Apr 4Last frostmedian Mar 19First fall frost: 9 in 10 years before Dec 6, half of years Nov 20, 1 in 10 years before Nov 5First frostmedian Nov 20Frost riskHardyHardy vegetables: plant Feb 19 to Mar 5Feb 19 to Mar 5Semi-hardySemi-hardy vegetables: plant Mar 5 to Mar 19Mar 5 to Mar 19TenderTender vegetables: plant around Mar 19around Mar 19Very tenderVery tender vegetables: plant from Apr 2from Apr 2
Shaded: the span between the dates frost passes in 9 of 10 years and 1 of 10 years[2][3]. Green: planting windows from the CSU rules applied to the median last frost (GardenFacts calculation)[6]. Exact dates are in the tables below.

These frost dates are odds from NOAA records for 1991 to 2020, not a forecast[5]. In 9 of 10 years the last spring frost comes after February 26, in half of years after March 19, and in 1 of 10 years after April 4[2]. In the fall, the first frost comes before November 5 in 1 of 10 years, before November 20 in half of years, and before December 6 in 9 of 10 years[3]. The numbers come from the Wilmington International Airport weather station[5]. Any single year can be earlier or later.

Frost Likely (9 in 10 years) Even odds (5 in 10) Unlikely (1 in 10)
Last spring frost (32°F)[2] after February 26 after March 19 after April 4
First fall frost (32°F)[3] before November 5 before November 20 before December 6
  • Hard freeze (28°F): median last spring date March 2, median first fall date December 3[7].
  • Frost-free growing season: at least 223 days in 9 of 10 years, 247 days in half of years and 274 days in 1 of 10 years[4].
  • The low reached 32°F or colder in 100% of years and 28°F or colder in 100% of years[8].
  • Weather station: Wilmington International Airport (USW00013748), 4.1 miles from the city center, 33 feet, 28 years of 1991 to 2020 records[5].

When to plant vegetables

Colorado State University Extension's planting guide was written for Colorado, so GardenFacts used its rules with Wilmington's NOAA median last frost of March 19[6]. Hardy vegetables such as broccoli, lettuce, peas and spinach can go in as early as 2 to 4 weeks before that date, which works out to February 19 to March 5[6]. Semi-hardy vegetables such as beets, carrots and potatoes can go in as early as 2 weeks before it, from March 5 up to the median date[9]. Tender vegetables such as snap beans and sweet corn can be planted from seed around March 19[10]. Very tender vegetables such as tomatoes and peppers typically start 2 or more weeks after the median last frost, and April 2 is the earliest start[11].

  • Hardy (broccoli, cabbage, kohlrabi, lettuce, onions, peas, radishes, spinach, turnips): as early as 2 to 4 weeks before the median last frost (March 19) is February 19 to March 5[6]
  • Semi-hardy (beets, carrots, cauliflower, parsnips, potatoes, Swiss chard): as early as 2 weeks before the median last frost (March 19) is March 5, up to the median date itself[9]
  • Tender (snap beans, sweet corn, cucumbers, summer squash): from seed around the median last frost date, March 19[10]
  • Very tender (cantaloupe, eggplant, peppers, tomatoes, winter squash, watermelon): the earliest start, two weeks after the median last frost (March 19), is April 2[11]
Vegetable (CSU group) Plant from First harvest around
Broccoli (hardy)[12] Feb 19 Apr 25 (from transplants)
Cabbage (hardy)[12] Feb 19 May 15 (from transplants)
Kohlrabi (hardy)[12] Feb 19 Apr 10
Lettuce (hardy)[12] Feb 19 Apr 20
Onions (hardy)[12] Feb 19 Jun 9
Peas (hardy)[12] Feb 19 Apr 25
Radishes (hardy)[12] Feb 19 Mar 21
Spinach (hardy)[12] Feb 19 Mar 31
Turnips (hardy)[12] Feb 19 Apr 10
Beets (semi-hardy)[12] Mar 5 May 4
Carrots (semi-hardy)[12] Mar 5 May 14
Cauliflower (semi-hardy)[12] Mar 5 not listed
Parsnips (semi-hardy)[12] Mar 5 May 14
Potatoes (semi-hardy)[12] Mar 5 Jul 8
Swiss chard (semi-hardy)[12] Mar 5 May 4
Snap beans (tender)[12] Mar 19 May 18
Sweet corn (tender)[12] Mar 19 May 18
Cucumbers (tender)[12] Mar 19 May 13
Summer squash (tender)[12] Mar 19 May 8
Cantaloupe (very tender)[12] Apr 2 Jun 26
Eggplant (very tender)[12] Apr 2 Jun 1 (from transplants)
Peppers (very tender)[12] Apr 2 Jun 11 (from transplants)
Tomatoes (very tender)[12] Apr 2 Jun 6 (from transplants)
Winter squash (very tender)[12] Apr 2 Jul 11
Watermelon (very tender)[12] Apr 2 Jun 26
Spacing, depth and soil temperature (CSU Extension)
Vegetable Min. soil temp Depth Spacing Days to harvest
Broccoli[13] 40°F 1/2 in 18 in 65
Cabbage[13] 40°F 1/2 in 18 in 85
Kohlrabi[13] 40°F 1/2 in 7-9 in 50
Lettuce[13] 35°F 1/4 in 7-9 in 60
Onions[13] 35°F 1/4 in (seed), 1-2 in (sets) 4-6 in 110
Peas[13] 40°F 1 in 4-6 in 65
Radishes[13] 40°F 1/2 in 2-3 in 30
Spinach[13] 40°F 1/2 in 4-6 in 40
Turnips[13] 40°F 1/2 in 4-6 in 50
Beets[13] 40°F 3/4-1 in 4-6 in 60
Carrots[13] 40°F 1/4 in 2-3 in 70
Cauliflower[13] 40°F 1/2 in 18 in –
Parsnips[13] 35°F 1/2 in 5-6 in 70
Potatoes[13] 45°F – – 125
Swiss chard[13] 40°F 1 in 7-9 in 60
Snap beans[13] 55°F 1-1 1/2 in 6 in 60
Sweet corn[13] 50°F 1-1 1/2 in 12 x 30 in or 9 x 36 in 60-90
Cucumbers[13] 60°F 1 in 6 in trellised, 24-36 in untrellised 55
Summer squash[13] 60°F 1-1 1/2 in 36-48 in 50
Cantaloupe[13] 60°F 1-1 1/2 in 36-48 in 85
Eggplant[13] 60°F 1/4 in 18-24 in 60
Peppers[13] 60°F 1/4 in 15-18 in 70
Tomatoes[13] 50°F 1/4 in 24 in trellised 65
Winter squash[13] 60°F 1-1 1/2 in 36-48 in 100
Watermelon[13] 60°F 1-1 1/2 in 36-48 in 85

Hardiness zone

The 2023 USDA map puts the center of Wilmington in zone 8b, which means an average coldest night of 15°F to 20°F over 1991 to 2020[1]. The zone is based on the coldest winter night, not on summer heat or frost dates[14]. All 6 ZIP code areas that overlap the city are rated zone 8b by land area, so the city does not span more than one zone[15].

Zone 8b: average annual extreme minimum temperature 15°F to 20°F (1991 to 2020)[1]. Modeled value at the city center: 17.2°F[1].

Share of the city's land area by ZIP code zone: zone 8b 100%[15].

All towns in zone 8b and what zone 8b means

Zone by ZIP code
ZIP code Zone Coldest night range
28403[15] 8b 15 to 20°F
28405[15] 8b 15 to 20°F
28412[15] 8b 15 to 20°F
28409[15] 8b 15 to 20°F
28401[15] 8b 15 to 20°F
28411[15] 8b 15 to 20°F

Questions people ask

What growing zone is Wilmington, NC?
The 2023 USDA Plant Hardiness Zone Map puts the center of Wilmington in zone 8b[1]. All of the city's land area lies in ZIP code areas rated 8b[15].
When is the last frost in Wilmington, NC?
The median last spring frost is March 19, so in half of years the last frost comes after that date[2]. In 1 of 10 years it comes after April 4[2].
When to plant tomatoes in Wilmington, NC?
CSU Extension says very tender vegetables like tomatoes typically start 2 or more weeks after the average last frost[11]. GardenFacts calculated the earliest start for Wilmington as April 2, using the median last frost of March 19[11]. CSU's guide was written for Colorado[11].
When is the first frost in Wilmington, NC?
The median first fall frost is November 20, so in half of years the first frost comes before that date[3]. In 1 of 10 years it comes before November 5[3].
How long is the growing season in Wilmington, NC?
The growing season is at least 247 days in half of years[4]. It is at least 223 days in 9 of 10 years[4].

Facts and sources

  1. The 2023 USDA Plant Hardiness Zone Map puts the center of Wilmington, North Carolina in zone 8b. Zone 8b means an average annual extreme minimum temperature of 15°F to 20°F over 1991 to 2020. The map's modeled value at the city center is 17.2°F. USDA zone map 2023 (PRISM, OSU)
  2. Last spring frost (32°F) at this station: in 9 of 10 years the last frost comes after February 26, in half of years after March 19, and in 1 of 10 years after April 4 (NOAA 1991 to 2020 normals). The median last frost date is March 19. NOAA Climate Normals 1991-2020
  3. First fall frost (32°F) at this station: in 1 of 10 years the first frost comes before November 5, in half of years before November 20, and in 9 of 10 years before December 6 (NOAA 1991 to 2020 normals). The median first frost date is November 20. NOAA Climate Normals 1991-2020
  4. Growing season (days between the last spring and first fall 32°F frost) at this station: at least 223 days in 9 of 10 years, at least 247 days in half of years, and at least 274 days in 1 of 10 years. NOAA Climate Normals 1991-2020
  5. Frost dates on this page come from NOAA climate normals for the Wilmington International Airport weather station (USW00013748), 4.1 miles from the center of Wilmington at 33 feet, using 28 years of records from 1991 to 2020. NOAA Climate Normals 1991-2020
  6. Colorado State University Extension's vegetable planting guide (written for Colorado) groups broccoli, cabbage, kohlrabi, lettuce, onions, peas, radishes, spinach, turnips as hardy vegetables, with this rule: as early as 2-4 weeks before the average last... CSU Extension GardenNotes #720
  7. Hard freeze (28°F) at this station: the median last spring date is March 2 and the median first fall date is December 3. NOAA Climate Normals 1991-2020
  8. At this station the low reached 32°F or colder in 100% of years from 1991 to 2020, and 28°F or colder in 100% of years. NOAA Climate Normals 1991-2020
  9. Colorado State University Extension's vegetable planting guide (written for Colorado) groups beets, carrots, cauliflower, parsnips, potatoes, Swiss chard as semi-hardy vegetables, with this rule: as early as 0-2 weeks before the average last spring frost.... CSU Extension GardenNotes #720
  10. Colorado State University Extension's vegetable planting guide (written for Colorado) groups snap beans, sweet corn, cucumbers, summer squash as tender vegetables, with this rule: from seed around the average last spring frost; cucumber and summer squash... CSU Extension GardenNotes #720
  11. Colorado State University Extension's vegetable planting guide (written for Colorado) groups cantaloupe, eggplant, peppers, tomatoes, winter squash, watermelon as very tender vegetables, with this rule: typically 2 or more weeks after the average last... CSU Extension GardenNotes #720
  12. GardenFacts calculation: earliest planting date plus CSU days to harvest (table on this page), from the station's median last frost. NOAA Climate Normals 1991-2020
  13. CSU Extension vegetable table: soil temperature, depth, spacing, days to harvest (table on this page). CSU Extension GardenNotes #720
  14. USDA hardiness zones are based on the average annual extreme minimum winter temperature (the coldest night of each winter, averaged over 1991 to 2020 for the 2023 map), not on summer heat or frost dates. Each zone spans 10°F and each half zone (a or b)... USDA Plant Hardiness Zone Map
  15. Wilmington, North Carolina overlaps 6 ZIP code areas. By land area, 100% lies in ZIP code areas rated zone 8b. USDA zone map 2023 (PRISM, OSU)

Frost dates are probabilities from 1991 to 2020 weather records at one NOAA station, not a forecast. Any year can be earlier or later. The hardiness zone describes the average coldest winter night, not frost dates or summer heat. Spots inside the city can differ (ZIP table). Planting rules come from Colorado State University Extension's guide, written for Colorado. A local extension office may give dates tuned to the area. Planting and harvest dates marked GardenFacts calculation are simple arithmetic from the facts above, not advice from the source.

Hardiness zone data: USDA Plant Hardiness Zone Map (2023), USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu, accessed October 30, 2026. This is not the official USDA map. Frost data: NOAA NCEI U.S. Climate Normals 1991-2020. Planting rules: Colorado State University Extension.