USDA Hardiness Zone 9a
Frost Dates for 36618 — Mobile, Alabama
NOAA 1991–2020 normals from Mobile, AL (208 ft), 5 miles southwest.
Updated
In Mobile, the last spring frost (32°F) is around March 3 in half of years and has passed by March 21 in nine years out of ten. The first fall frost comes around November 25, as early as November 8 one year in ten, leaving a typical freeze-free season of 268 days (NOAA, Mobile, AL).
- Last spring frost
- March 3
- First fall frost
- November 25
- Growing season
- 268 days
- Hardiness zone
- 9a
50% probability
50% probability
freeze-free, 50%
20 to 25°F (-6.7 to -3.9°C) coldest night
- First snow
- Rare
- Last snow
- Rare
- Winters with snow
- 20%
- Snow per year
- 0.2"
median, 1991–2020
median, 1991–2020
6 of 30 observed
NOAA normal
Frost risk by date in Mobile
Half of springs at Mobile, AL see their last 32°F night by March 3; only one in ten is past it by February 6, and one in ten still has one after March 21. Planting tender crops after March 12 leaves a 30% risk of a frost on them, after March 16 20%, and after March 21 10%. The 18 days between the even-odds date and the one-in-ten date is narrower than at 46% of the 115 Alabama stations behind this site's ZIP pages.
In fall the first 32°F night comes by November 25 in half of years, as early as November 8 one year in ten, and holds off past December 22 one year in ten. A hard freeze of 28°F follows 19 days later, around December 14; in spring the one-in-ten date for 28°F is March 13, 8 days before the 32°F one. The freeze-free season lasts 268 days in a typical year, longer than at 93% of the 115 Alabama stations; it reaches 300 days one year in ten and falls short of 242 one year in ten. On average 21 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 14 days longer, to about March 17, and return around November 13. Nights of 24°F, cold enough to damage hardier plants, come in 81% of winters and 16°F in 14%.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Feb 26 | Mar 5 | Mar 10 | Mar 14 | Mar 17 | Mar 20 | Mar 25 | Mar 30 | Apr 5 |
| 32°F | Feb 6 | Feb 15 | Feb 22 | Feb 27 | Mar 3 | Mar 8 | Mar 12 | Mar 16 | Mar 21 |
| 28°F99% of yrs | Jan 17 | Jan 28 | Feb 2 | Feb 6 | Feb 13 | Feb 21 | Feb 28 | Mar 6 | Mar 13 |
| 24°F81% of yrs | Dec 31 | Jan 12 | Jan 18 | Jan 25 | Jan 30 | Feb 2 | Feb 9 | Feb 19 | Mar 2 |
| 20°F44% of yrs | too rare for a date | ||||||||
| 16°F14% of yrs | too rare for a date | ||||||||
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 30 | Nov 3 | Nov 6 | Nov 10 | Nov 13 | Nov 16 | Nov 20 | Nov 26 | Dec 4 |
| 32°F | Nov 8 | Nov 13 | Nov 17 | Nov 21 | Nov 25 | Dec 1 | Dec 4 | Dec 10 | Dec 22 |
| 28°F99% of yrs | Nov 17 | Nov 26 | Dec 2 | Dec 7 | Dec 14 | Dec 24 | Jan 1 | Jan 7 | Jan 17 |
| 24°F81% of yrs | Dec 4 | Dec 13 | Dec 23 | Dec 30 | Jan 3 | Jan 8 | Jan 14 | Jan 21 | Feb 3 |
| 20°F44% of yrs | too rare for a date | ||||||||
| 16°F14% of yrs | too rare for a date | ||||||||
Freeze probabilities 1991–2020 at Mobile, AL, 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 36618 →Compare Mobile with another place →
Weather by month in Mobile
July is the warmest month at Mobile, AL, averaging 91°F by day and 73°F at night; January is the coldest at 62°F and 41°F. A freezing night is all but certain in January (a 90% chance or more). From April to October the chance of a 32°F night stays under 10% each month. In spring, February still brings one in 86% of years and March still brings one in 56% of years.
Warmth for growing adds up to 6,719 growing degree days a year (base 50°F), more than at 94% of the 115 Alabama stations. 42% of them (2,842) have built up by the end of June, and July adds the most, 992. Precipitation totals 67.3 inches a year, most in July (7.7") and least in October (4.0"); May to September bring 47% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 62 | 41 | 5.7 | 97% | 8 | 139 |
| Feb | 66 | 44 | 4.5 | 86% | 4 | 186 |
| Mar | 72 | 50 | 5.4 | 56% | 2 | 351 |
| Apr | 78 | 56 | 5.7 | 0% | 0 | 508 |
| May | 85 | 64 | 5.4 | 0% | 0 | 755 |
| Jun | 89 | 71 | 6.6 | 0% | 0 | 903 |
| Jul | 91 | 73 | 7.7 | 0% | 0 | 992 |
| Aug | 91 | 73 | 6.9 | 0% | 0 | 987 |
| Sep | 88 | 69 | 5.3 | 0% | 0 | 844 |
| Oct | 80 | 58 | 4.0 | 2% | <1 | 589 |
| Nov | 70 | 48 | 4.6 | 58% | 2 | 289 |
| Dec | 64 | 43 | 5.5 | 87% | 6 | 176 |
Monthly normals 1991–2020 at Mobile, AL (208 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, Mobile Dwtn Airport, AL, 9 miles southeast of Mobile and 182 feet lower, has a last frost 10 days earlier (February 21), a first frost 11 days later (December 6), a season 24 days longer.
When it snows in Mobile, Alabama
Measurable snow is rare here: only 6 of 30 winters from 1991 to 2020 recorded 0.1 inch or more at Mobile, AL, 5.4 miles away, so there is no typical first-snow date to plan around.
Planting calendar for 36618
| When | What to do |
|---|---|
| December 23 – January 6 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| January 6 – January 20 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| February 3 – February 17 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| March 3 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by September 2 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by November 11 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| November 25 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 36618 is 5 miles from Mobile, AL, which stands at 208 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 11 other ZIP codes share the station; its figures are presented in full for 36695 (Mobile). The 2023 USDA Plant Hardiness Zone Map lists ZIP 36618 in zone 9a, the band where the coldest night of the year averaged 20 to 25°F (-6.7 to -3.9°C) over 1991–2020; a zone describes winter lows, not frost dates.
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.