Frost dates for Mobile, Alabama
In Mobile, half of springs have had their last frost by February 21 (and 1 spring in 10 still has one after March 15), and half of falls have had their first frost by December 6, leaving about 292 frost-free days in a typical year. Here is how sure those dates are, what they mean for planting, and where they come from.
Frost dates for
Mobile, Alabama
Last spring frost
February 21
Half of springs have their last frost by this date. For a safer bet, wait until March 15: only 1 spring in 10 has a frost after that.
First fall frost
December 6
Half of falls have their first frost by this date. In 1 fall in 10 it comes by November 15.
Growing season
292 days
Frost-free days in a typical year. 9 years in 10 get at least 257.
Hardiness zone
9a
2023 USDA map: the coldest night of winter averages 20°F to 25°F. On the 2012 map it was 8b, half a zone colder. All 16 ZIP codes within about 6 miles of the city's center are in zone 9a.
Print a year planner for Mobile
Frost risk through the year
How sure are these dates?
A frost date is a probability, not a promise. NOAA worked out, from 30 years of nightly lows, how often the last spring frost and the first fall frost fall on each date. The middle column is the typical year. The outer columns are the early and late years that come about once a decade.
| Early year 1 in 10 | Typical year 1 in 2 | Late year 1 in 10 | |
|---|---|---|---|
| Last frost in spring | January 25 | February 21 | March 15 |
| First frost in fall | November 15 | December 6 | January 5 |
The frost-free season between them runs 292 days in a typical year. In 1 year in 10 it is 326 days or longer, and in 1 year in 10 it is 257 days or shorter.
- Hard freeze (28°F): about 89 years in 100 have one. In those years the last typically comes on February 2 and the first on December 30. It is a harder freeze than the 32°F frost line, cold enough to damage many garden plants; how hardy a crop is decides whether it comes through. (The National Weather Service's own hard-freeze threshold varies from office to office.)
- Frost possible (36°F at the station): typically last on March 6 and first on November 22. On clear, still nights the ground can be several degrees colder than the thermometer, so frost can form on plants when the official reading is in the mid-30s.
In 8 springs out of 10, the last frost in Mobile comes between January 25 and March 15, a window of 49 days. That is wider than at most NOAA stations (the typical window is 31 days), so spring here is less predictable than average: lean toward the later date.
Among Alabama's 117 NOAA stations with a frost every year, 99 percent have their typical last frost later than Mobile does.
Planting calendar for Mobile
These dates count from the typical last and first frosts, using the planting rules published by Colorado State University Extension (spring), Virginia Cooperative Extension (fall crops) and University of Minnesota Extension (garlic, where winters are hard). Weather in any one year can run early or late, so check the forecast before you plant tender crops.
We don't give a garlic date here. The rule we use, from the University of Minnesota Extension, counts from the first killing frost, and it works where a hard freeze comes every year before the ground freezes. Your county's extension office can tell you when to plant garlic in your climate.
| When | What to do | Why then |
|---|---|---|
| January | ||
| January 3 to 24 | Eggplant Start seeds indoors | 6 to 9 weeks before planting out |
| January 10 to 24 | Peppers Start seeds indoors | 6 to 8 weeks before planting out |
| January 17 to 31 | Tomatoes Start seeds indoors | 5 to 7 weeks before planting out |
| January 24 to February 7 | Peas, spinach, lettuce, radishes, onion sets, turnips Sow outdoors, as early as | hardy crops: 2 to 4 weeks before the typical last frost |
| January 24 to February 7 | Broccoli and cabbage Plant out, as early as | hardy crops: 2 to 4 weeks before the typical last frost |
| February | ||
| February 7 to 21 | Beets, carrots, potatoes, Swiss chard Plant outdoors, as early as | semi-hardy crops: up to 2 weeks before the typical last frost |
| February 7 to 21 | Cauliflower Plant out, as early as | semi-hardy: up to 2 weeks before the typical last frost |
| February 21 | Snap beans, sweet corn, cucumbers, summer squash Sow outdoors around | tender crops: around the typical last frost date |
| March | ||
| March 7 | Tomatoes, peppers, eggplant Plant out from | very tender: 2 weeks or more after the typical last frost |
| March 7 | Melons, winter squash, pumpkins, lima beans Sow outdoors from | very tender: 2 weeks or more after the typical last frost |
| July | ||
| July 11 to 25 | Cabbage for fall Start seeds | set the plants out by August 29 |
| July 31 to August 14 | Broccoli for fall Start seeds | set the plants out by September 18 |
| September | ||
| September 9 | Snap beans for fall Last date to sow | 60 days to harvest, plus 2 weeks for slower fall growth, plus 2 weeks because frost kills it |
| September 13 | Carrots for fall Last date to sow | 70 days to harvest, plus 2 weeks for slower fall growth |
| September 14 | Cucumbers for fall Last date to sow | 55 days to harvest, plus 2 weeks for slower fall growth, plus 2 weeks because frost kills it |
| September 18 | Peas for fall Last date to sow | 65 days to harvest, plus 2 weeks for slower fall growth |
| September 19 | Summer squash for fall Last date to sow | 50 days to harvest, plus 2 weeks for slower fall growth, plus 2 weeks because frost kills it |
| September 23 | Leaf lettuce and beets for fall Last date to sow | 60 days to harvest, plus 2 weeks for slower fall growth |
| October | ||
| October 3 | Turnips and kohlrabi for fall Last date to sow | 50 days to harvest, plus 2 weeks for slower fall growth |
| October 13 | Spinach for fall Last date to sow | 40 days to harvest, plus 2 weeks for slower fall growth |
| October 23 | Radishes for fall Last date to sow | 30 days to harvest, plus 2 weeks for slower fall growth |
| November | ||
| November 15 | Tomatoes, peppers, squash, melons, cucumbers Watch the forecast from | in 1 fall in 10 the first frost comes by this date; pick tender crops before a frost |
| December | ||
| December 6 to January 3 | Broccoli and cabbage Start seeds indoors | 5 to 7 weeks before planting them out |
| December 20 to January 17 | Cauliflower Start seeds indoors | 5 to 7 weeks before planting out |
Want more insurance? Shift every spring date 22 days later. That plans around March 15, the date after which only 1 spring in 10 has a frost.
For spring bulbs such as tulips and daffodils, plant once the soil has cooled to about 50 to 55°F and keep going until a couple of weeks before the ground freezes. Our guide to fall planting explains how to tell.
Where these numbers come from
These dates come from NOAA's weather station Mobile Downtown Airport (station USW00013838), 4 miles from the center of Mobile. It sits at about the same elevation, 30 feet above sea level. NOAA rates this station's record as standard: at least 24 of the 30 years, with gaps filled from nearby stations.
The same station also gives the frost dates for Prichard.
Our ZIP code lookup matches these 15 ZIP codes to the same station, so they get the same dates: 36572, 36602, 36603, 36604, 36605, 36606, 36607, 36610, 36611, 36612, 36615, 36617, 36652, 36663, 36693. Hardiness zones are worked out separately for each ZIP code.
The nearest other places with pages
- Gulfport, Mississippi: last frost around February 23, first frost around December 3 (60 miles away)
- Hattiesburg, Mississippi: last frost around March 8, first frost around November 15 (85 miles away)
- New Orleans, Louisiana: frost not every year (115 miles away)
See frost dates across Alabama, or look up your own ZIP code for the station nearest you. Want the background? Read what a last frost date really means.