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Frost dates and planting calendar for Birmingham, Alabama

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

USDA hardiness zone
8a[1]
Median last spring frost
Mar 21[2]
Median first fall frost
Nov 11[3]
Growing season, median
236 days[4]

Birmingham, Alabama is in USDA hardiness zone 8a[1]. The median last spring frost is March 21[2].

Frost dates

JanFebMarAprMayJunJulAugSepOctNovDecLast spring frost: 9 in 10 years after Feb 28, half of years Mar 21, 1 in 10 years after Apr 8Last frostmedian Mar 21First fall frost: 9 in 10 years before Dec 1, half of years Nov 11, 1 in 10 years before Oct 30First frostmedian Nov 11Frost riskHardyHardy vegetables: plant Feb 21 to Mar 7Feb 21 to Mar 7Semi-hardySemi-hardy vegetables: plant Mar 7 to Mar 21Mar 7 to Mar 21TenderTender vegetables: plant around Mar 21around Mar 21Very tenderVery tender vegetables: plant from Apr 4from Apr 4
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.

Frost dates here are odds, not promises. They come from NOAA climate normals for the Birmingham Airport weather station, using records from 1991 to 2020[5]. In half of years the last spring frost comes after March 21, and in 1 of 10 years it comes after April 8[2]. In half of years the first fall frost comes before November 11, and in 1 of 10 years it comes before October 30[3]. Any year can be earlier or later than these dates[2].

Frost Likely (9 in 10 years) Even odds (5 in 10) Unlikely (1 in 10)
Last spring frost (32°F)[2] after February 28 after March 21 after April 8
First fall frost (32°F)[3] before October 30 before November 11 before December 1
  • Hard freeze (28°F): median last spring date March 7, median first fall date November 24[7].
  • Frost-free growing season: at least 211 days in 9 of 10 years, 236 days in half of years and 262 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: Birmingham Airport (USW00013876), 4 miles from the city center, 615 feet, 28 years of 1991 to 2020 records[5].

When to plant vegetables

Colorado State University Extension's planting guide was written for Colorado[6]. GardenFacts used it with the median last frost date of March 21 to work out dates for Birmingham[6]. Hardy vegetables such as broccoli, lettuce and peas can go in as early as 2 to 4 weeks before the median last frost, which is February 21 to March 7[6]. Semi-hardy vegetables such as beets, carrots and potatoes can go in as early as 2 weeks before it, which is March 7[9]. Tender vegetables such as snap beans and sweet corn can be started from seed around March 21[10]. Very tender vegetables such as tomatoes and peppers typically wait 2 or more weeks after the median last frost, so the earliest start is April 4[11].

  • Hardy (broccoli, cabbage, kohlrabi, lettuce, onions, peas, radishes, spinach, turnips): as early as 2 to 4 weeks before the median last frost (March 21) is February 21 to March 7[6]
  • Semi-hardy (beets, carrots, cauliflower, parsnips, potatoes, Swiss chard): as early as 2 weeks before the median last frost (March 21) is March 7, up to the median date itself[9]
  • Tender (snap beans, sweet corn, cucumbers, summer squash): from seed around the median last frost date, March 21[10]
  • Very tender (cantaloupe, eggplant, peppers, tomatoes, winter squash, watermelon): the earliest start, two weeks after the median last frost (March 21), is April 4[11]
Vegetable (CSU group) Plant from First harvest around
Broccoli (hardy)[12] Feb 21 Apr 27 (from transplants)
Cabbage (hardy)[12] Feb 21 May 17 (from transplants)
Kohlrabi (hardy)[12] Feb 21 Apr 12
Lettuce (hardy)[12] Feb 21 Apr 22
Onions (hardy)[12] Feb 21 Jun 11
Peas (hardy)[12] Feb 21 Apr 27
Radishes (hardy)[12] Feb 21 Mar 23
Spinach (hardy)[12] Feb 21 Apr 2
Turnips (hardy)[12] Feb 21 Apr 12
Beets (semi-hardy)[12] Mar 7 May 6
Carrots (semi-hardy)[12] Mar 7 May 16
Cauliflower (semi-hardy)[12] Mar 7 not listed
Parsnips (semi-hardy)[12] Mar 7 May 16
Potatoes (semi-hardy)[12] Mar 7 Jul 10
Swiss chard (semi-hardy)[12] Mar 7 May 6
Snap beans (tender)[12] Mar 21 May 20
Sweet corn (tender)[12] Mar 21 May 20
Cucumbers (tender)[12] Mar 21 May 15
Summer squash (tender)[12] Mar 21 May 10
Cantaloupe (very tender)[12] Apr 4 Jun 28
Eggplant (very tender)[12] Apr 4 Jun 3 (from transplants)
Peppers (very tender)[12] Apr 4 Jun 13 (from transplants)
Tomatoes (very tender)[12] Apr 4 Jun 8 (from transplants)
Winter squash (very tender)[12] Apr 4 Jul 13
Watermelon (very tender)[12] Apr 4 Jun 28
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

Zone 8a means the coldest night of the year averages 10°F to 15°F, based on 1991 to 2020[1]. The zone comes from winter lows, not from frost dates or summer heat[14]. Most of Birmingham's land area is in ZIP code areas rated 8a, and some is in areas rated 8b, so the city spans more than one zone[15].

Zone 8a: average annual extreme minimum temperature 10°F to 15°F (1991 to 2020)[1]. Modeled value at the city center: 14.5°F[1].

Share of the city's land area by ZIP code zone: zone 8a 71%, zone 8b 28%[15].

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

Zone by ZIP code
ZIP code Zone Coldest night range
35211[15] 8b 15 to 20°F
35206[15] 8a 10 to 15°F
35214[15] 8a 10 to 15°F
35215[15] 8a 10 to 15°F
35207[15] 8a 10 to 15°F
35210[15] 8a 10 to 15°F
35242[15] 8b 15 to 20°F
35094[15] 8a 10 to 15°F
35212[15] 8a 10 to 15°F
35235[15] 8a 10 to 15°F
35224[15] 8b 15 to 20°F
35204[15] 8a 10 to 15°F
35217[15] 8a 10 to 15°F
35222[15] 8a 10 to 15°F
35205[15] 8b 15 to 20°F
35208[15] 8a 10 to 15°F
35130[15] 8a 10 to 15°F
35234[15] 8a 10 to 15°F
35068[15] 8a 10 to 15°F
35022[15] 8b 15 to 20°F
35218[15] 8a 10 to 15°F
35221[15] 8a 10 to 15°F
35209[15] 8b 15 to 20°F
35203[15] 8a 10 to 15°F
35213[15] 8b 15 to 20°F
35243[15] 8b 15 to 20°F
35118[15] 8a 10 to 15°F
35233[15] 8a 10 to 15°F
35228[15] 8a 10 to 15°F
35061[15] 8a 10 to 15°F

Questions people ask

What growing zone is Birmingham, Alabama?
The 2023 USDA map puts the center of Birmingham in zone 8a[1]. By land area, 71% of the city is in ZIP code areas rated 8a and 28% in areas rated 8b[15].
When is the last frost in Birmingham?
The median last spring frost is March 21, so in half of years the last frost comes after that date[2]. In 1 of 10 years it comes after April 8[2].
When is the first frost in Birmingham?
The median first fall frost is November 11[3]. In 1 of 10 years the first frost comes before October 30[3].
When to plant tomatoes in Birmingham?
CSU Extension typically has very tender vegetables like tomatoes wait 2 or more weeks after the average last frost, and its guide was written for Colorado[11]. Using the median last frost, the earliest start is April 4[11].
How long is the growing season in Birmingham?
The growing season is at least 236 days in half of years[4]. It is at least 211 days in 9 of 10 years[4].

Facts and sources

  1. The 2023 USDA Plant Hardiness Zone Map puts the center of Birmingham, Alabama in zone 8a. Zone 8a means an average annual extreme minimum temperature of 10°F to 15°F over 1991 to 2020. The map's modeled value at the city center is 14.5°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 28, in half of years after March 21, and in 1 of 10 years after April 8 (NOAA 1991 to 2020 normals). The median last frost date is March 21. NOAA Climate Normals 1991-2020
  3. First fall frost (32°F) at this station: in 1 of 10 years the first frost comes before October 30, in half of years before November 11, and in 9 of 10 years before December 1 (NOAA 1991 to 2020 normals). The median first frost date is November 11. NOAA Climate Normals 1991-2020
  4. Growing season (days between the last spring and first fall 32°F frost) at this station: at least 211 days in 9 of 10 years, at least 236 days in half of years, and at least 262 days in 1 of 10 years. NOAA Climate Normals 1991-2020
  5. Frost dates on this page come from NOAA climate normals for the Birmingham Airport weather station (USW00013876), 4 miles from the center of Birmingham at 615 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 7 and the median first fall date is November 24. 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. Birmingham, Alabama overlaps 40 ZIP code areas. By land area, 71% lies in ZIP code areas rated zone 8a, 28% 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.