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Frost dates and planting calendar for Columbia, Missouri

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

USDA hardiness zone
6b[1]
Median last spring frost
Apr 5[2]
Median first fall frost
Oct 31[3]
Growing season, median
207 days[4]

Columbia, Missouri is in USDA hardiness zone 6b[1]. In half of years the last spring frost comes after April 5, which is the NOAA median[2].

Frost dates

JanFebMarAprMayJunJulAugSepOctNovDecLast spring frost: 9 in 10 years after Mar 19, half of years Apr 5, 1 in 10 years after Apr 21Last frostmedian Apr 5First fall frost: 9 in 10 years before Nov 14, half of years Oct 31, 1 in 10 years before Oct 17First frostmedian Oct 31Frost riskHardyHardy vegetables: plant Mar 8 to Mar 22Mar 8 to Mar 22Semi-hardySemi-hardy vegetables: plant Mar 22 to Apr 5Mar 22 to Apr 5TenderTender vegetables: plant around Apr 5around Apr 5Very tenderVery tender vegetables: plant from Apr 19from Apr 19
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 come from NOAA climate normals for the Columbia U Of M weather station, using records from 1991 to 2020[5]. In 9 of 10 years the last spring frost comes after March 19, and in 1 of 10 years it comes after April 21[2]. In half of years the first fall frost comes before October 31, and in 1 of 10 years it comes before October 17[3]. These are chances from past records and not a forecast, so any year can be earlier or later[5].

Frost Likely (9 in 10 years) Even odds (5 in 10) Unlikely (1 in 10)
Last spring frost (32°F)[2] after March 19 after April 5 after April 21
First fall frost (32°F)[3] before October 17 before October 31 before November 14
  • Hard freeze (28°F): median last spring date March 26, median first fall date November 9[7].
  • Frost-free growing season: at least 187 days in 9 of 10 years, 207 days in half of years and 227 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: Columbia U Of M (USC00231801), 0.5 miles from the city center, 770 feet, 24 years of 1991 to 2020 records[5].

When to plant vegetables

Colorado State University Extension wrote its planting guide for Colorado, and GardenFacts applies its rules to Columbia using the median last frost of April 5[6]. Hardy vegetables such as broccoli, lettuce, peas and spinach can go in as early as 2 to 4 weeks before that date, which is March 8 to March 22[6]. Semi-hardy vegetables such as beets, carrots and potatoes can go in as early as 2 weeks before it, which is March 22[9]. Tender vegetables such as snap beans, sweet corn and cucumbers can be planted from seed around April 5[10]. Very tender vegetables such as tomatoes, peppers and eggplant typically wait 2 or more weeks after it, and the earliest start is April 19[11].

  • Hardy (broccoli, cabbage, kohlrabi, lettuce, onions, peas, radishes, spinach, turnips): as early as 2 to 4 weeks before the median last frost (April 5) is March 8 to March 22[6]
  • Semi-hardy (beets, carrots, cauliflower, parsnips, potatoes, Swiss chard): as early as 2 weeks before the median last frost (April 5) is March 22, up to the median date itself[9]
  • Tender (snap beans, sweet corn, cucumbers, summer squash): from seed around the median last frost date, April 5[10]
  • Very tender (cantaloupe, eggplant, peppers, tomatoes, winter squash, watermelon): the earliest start, two weeks after the median last frost (April 5), is April 19[11]
Vegetable (CSU group) Plant from First harvest around
Broccoli (hardy)[12] Mar 8 May 12 (from transplants)
Cabbage (hardy)[12] Mar 8 Jun 1 (from transplants)
Kohlrabi (hardy)[12] Mar 8 Apr 27
Lettuce (hardy)[12] Mar 8 May 7
Onions (hardy)[12] Mar 8 Jun 26
Peas (hardy)[12] Mar 8 May 12
Radishes (hardy)[12] Mar 8 Apr 7
Spinach (hardy)[12] Mar 8 Apr 17
Turnips (hardy)[12] Mar 8 Apr 27
Beets (semi-hardy)[12] Mar 22 May 21
Carrots (semi-hardy)[12] Mar 22 May 31
Cauliflower (semi-hardy)[12] Mar 22 not listed
Parsnips (semi-hardy)[12] Mar 22 May 31
Potatoes (semi-hardy)[12] Mar 22 Jul 25
Swiss chard (semi-hardy)[12] Mar 22 May 21
Snap beans (tender)[12] Apr 5 Jun 4
Sweet corn (tender)[12] Apr 5 Jun 4
Cucumbers (tender)[12] Apr 5 May 30
Summer squash (tender)[12] Apr 5 May 25
Cantaloupe (very tender)[12] Apr 19 Jul 13
Eggplant (very tender)[12] Apr 19 Jun 18 (from transplants)
Peppers (very tender)[12] Apr 19 Jun 28 (from transplants)
Tomatoes (very tender)[12] Apr 19 Jun 23 (from transplants)
Winter squash (very tender)[12] Apr 19 Jul 28
Watermelon (very tender)[12] Apr 19 Jul 13
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 USDA map puts the center of Columbia in zone 6b, which means an average coldest night of -5°F to 0°F from 1991 to 2020[1]. A zone is based on winter cold, not on summer heat or frost dates[14]. All 4 ZIP code areas that overlap the city are rated zone 6b by land area[15].

Zone 6b: average annual extreme minimum temperature -5°F to 0°F (1991 to 2020)[1]. Modeled value at the city center: -1.9°F[1].

Share of the city's land area by ZIP code zone: zone 6b 100%[15].

All towns in zone 6b and what zone 6b means

Zone by ZIP code
ZIP code Zone Coldest night range
65203[15] 6b -5 to 0°F
65202[15] 6b -5 to 0°F
65201[15] 6b -5 to 0°F
65216[15] 6b -5 to 0°F

Questions people ask

What growing zone is Columbia, Missouri?
The 2023 USDA map puts the center of Columbia in zone 6b[1]. All of the city's land area lies in ZIP code areas rated 6b[15].
When is the last frost in Columbia, Missouri?
In half of years the last spring frost comes after April 5, and in 9 of 10 years it comes after March 19[2]. In 1 of 10 years it comes after April 21[2].
When to plant tomatoes in Columbia, Missouri?
CSU Extension typically says very tender vegetables like tomatoes wait 2 or more weeks after the average last frost, and the earliest start for Columbia is April 19[11]. CSU's guide was written for Colorado[11].
When is the first frost in Columbia, Missouri?
In half of years the first fall frost comes before October 31[3]. In 1 of 10 years it comes before October 17[3].
How long is the growing season in Columbia, Missouri?
The growing season is at least 207 days in half of years, and at least 187 days in 9 of 10 years[4].

Facts and sources

  1. The 2023 USDA Plant Hardiness Zone Map puts the center of Columbia, Missouri in zone 6b. Zone 6b means an average annual extreme minimum temperature of -5°F to 0°F over 1991 to 2020. The map's modeled value at the city center is minus 1.9°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 March 19, in half of years after April 5, and in 1 of 10 years after April 21 (NOAA 1991 to 2020 normals). The median last frost date is April 5. 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 17, in half of years before October 31, and in 9 of 10 years before November 14 (NOAA 1991 to 2020 normals). The median first frost date is October 31. NOAA Climate Normals 1991-2020
  4. Growing season (days between the last spring and first fall 32°F frost) at this station: at least 187 days in 9 of 10 years, at least 207 days in half of years, and at least 227 days in 1 of 10 years. NOAA Climate Normals 1991-2020
  5. Frost dates on this page come from NOAA climate normals for the Columbia U Of M weather station (USC00231801), 0.5 miles from the center of Columbia at 770 feet, using 24 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 26 and the median first fall date is November 9. 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. Columbia, Missouri overlaps 4 ZIP code areas. By land area, 100% lies in ZIP code areas rated zone 6b. 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.