Metro areas

Gardening in New Orleans-Metairie, LA

This metro spans USDA zones 9a to 10a, so there is no single zone for New Orleans-Metairie, LA and anyone who gives you one is rounding. 82% of its ZIP codes are zone 9b; the rest are not.

USDA zones 9a–10a 3 zones across 71 ZIP codes
ZIP codes 71 71 have a NOAA station within range
Weather stations 15 NOAA 1991–2020 normals, across 2,359 sq mi

Which zone you are in depends where you are

New Orleans-Metairie, LA 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 82% in zone 9b and wrong for the other 18%. Here is the actual split.

Zone ZIP codes Share  
9b 58 82%
9a 8 11%
10a 5 7%

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 New Orleans-Metairie, LA, 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 15 stations serving New Orleans-Metairie, LA it runs 281–357 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 88–94 °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 New Orleans-Metairie, LA

Of 74 perennial fruits, nuts, berries, vegetables and herbs, 46 come through the winter in zone 9a and only 25 in zone 10a. That is a different garden at each end of the same metro.

Zone ZIPs Survive Fail for being too warm
9a 8 46 of 74 25
9b 58 40 of 74 32
10a 5 25 of 74 49

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 15 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
Boothville Asos, LA USW00012884 January 23 January 9 357 days
Buras, LA USC00161292 January 25 January 4 346 days
Chalmette, LA USC00166130 February 10 December 17 309 days
Donaldsonville 4 SW, LA USC00162534 February 21 December 5 291 days
Galliano, LA USC00163433 February 8 December 19 311 days
Lsu Citrus Rsch Stn, LA USC00165624 February 3 December 28 327 days
Marrero 9 Ssw, LA USC00165926 February 10 December 12 306 days
New Orleans Alvin Callender Fl, LA USW00012958 February 18 December 6 295 days
New Orleans Audubon, LA USW00012930 January 24 January 2 341 days
New Orleans INTL AP, LA USW00012916 January 30 December 31 333 days
New Orleans Lakefront AP, LA USW00053917 January 22 January 5 348 days
Reserve, LA USC00167767 February 9 December 14 308 days
Slidell, LA USC00168539 February 24 December 1 281 days
St Bernard, LA USC00168108 February 4 December 15 312 days
Terrytown 3S, LA USC00168941 February 1 December 31 330 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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