Metro areas

Gardening in Mobile, AL

This metro spans USDA zones 8b to 9b, so there is no single zone for Mobile, AL and anyone who gives you one is rounding. 79% of its ZIP codes are zone 9a; the rest are not.

USDA zones 8b–9b 3 zones across 38 ZIP codes
ZIP codes 38 38 have a NOAA station within range
Weather stations 6 NOAA 1991–2020 normals, across 1,229 sq mi

Which zone you are in depends where you are

Mobile, AL covers 3 hardiness zones. A guide that gives the metro one zone has picked whichever is largest and rounded everyone else into it — which is fine for the 79% in zone 9a and wrong for the other 21%. Here is the actual split.

Zone ZIP codes Share  
9a 30 79%
8b 7 18%
9b 1 3%

Zones are published per ZIP code, so yours is exact even though the metro's is not. The hardiness tool will tell you which one you are in.

Your freeze dates

No freeze range is shown for Mobile, AL, because the freeze window here crosses New Year, so an earliest-to-latest range would be arithmetic on dates that do not sit in order. The tools below still answer for individual ZIP codes here, and will say what applies.

Your growing season

NOAA publishes a growing-season length for each station, and across the 6 stations serving Mobile, AL it runs 228–340 days . That figure is published, not computed from the two freeze dates — subtracting one from the other gives the wrong answer wherever a season crosses New Year. Mean summer high (June–August) runs 88–91 °F , at or above the 90 °F point where cool-season crops bolt and tomato and pepper pollen fails — so midsummer sowings of lettuce and its relatives are worth holding here.

What survives the winter changes across Mobile, AL

Of 74 perennial fruits, nuts, berries, vegetables and herbs, 54 come through the winter in zone 8b and only 40 in zone 9b. That is a different garden at each end of the same metro.

Zone ZIPs Survive Fail for being too warm
8b 7 54 of 74 11
9a 30 46 of 74 25
9b 1 40 of 74 32

The last column is the counterintuitive one, and it is why the totals do not simply rise as the winters get milder. Most temperate fruit needs a documented number of hours below about 45 °F to break dormancy and set a crop, so an apple fails in a winter that is too warm; currants and rhubarb cook in the summer heat that comes with it. See the full list with reasons.

The 6 stations behind these numbers

Every figure above comes from these, and each is named so you can check it. Distances vary by ZIP code, so the tools report yours rather than this page guessing.

Station NOAA ID Last spring freeze First fall freeze Season
Bay Minette, AL USC00010583 February 28 November 25 272 days
Chatom, AL USC00011566 March 26 November 8 228 days
Coden, AL USC00011803 March 13 November 24 255 days
Dauphin Is #2, AL USC00012172 January 31 January 6 340 days
Mobile Dwtn AP, AL USW00013838 February 21 December 6 292 days
Mobile, AL USW00013894 March 3 November 25 268 days

These are medians, not averages — NOAA publishes freeze dates as a probability distribution, and half of years freeze later than the date shown.

Work out your own dates

Each of these takes a ZIP code and answers for that ZIP alone, citing the station it used and how far away it is. There is a ZIP box in the header of every page.

Where these numbers come from

The hardiness zone is the USDA 2023 Plant Hardiness Zone Map, published per ZIP code by PRISM at Oregon State. The freeze dates are NOAA's 1991–2020 Climate Normals, read from every station whose normals cover a ZIP code in this metro. Nothing here is estimated, and no station stands in for another.

This page names no single station on purpose. Picking one to represent a metro sounds reasonable and is not: the station serving the most ZIP codes is an artifact of where ZIP centroids happen to fall, and it selects a lock on the Monongahela for Pittsburgh and a far southern suburb for Chicago. A range across every station is true; a single cited date for a whole metro is not.

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