Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for 70401 — Hammond, LA

ZIP code 70401 (Hammond, Tangipahoa County) is in USDA zone 9a: the coldest winter night averages 20 to 25 °F. The median last spring frost is March 8 and the first fall frost November 19.

Where ZIP 70401 is

Outlined: the ZIP code area · tap the map for the zone at any spot · scroll or pinch to zoom

Not the official USDA Plant Hardiness Zone Map. Zones come from the 2023 USDA hardiness-zone data by the PRISM Group, Oregon State University; we re-mapped and recolored them. The official map is at planthardiness.ars.usda.gov.

Zone9a20 to 25 °F

Coldest night−6.7 to −3.9 °C

Last frostMar 8

First frostNov 19

2012 zone8b

Was 8b on the 2012 map — half a zone warmer now. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 9a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Hammond, LA…

Forecast data: National Weather Service (api.weather.gov), public domain. This is not a warning service — for official frost and freeze warnings see weather.gov.

Frost dates in Hammond, LA

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostMarch 8median — 50% chance of a later frost

Safe for tender plantsMarch 31only 10% chance of frost after

First fall frostNovember 19median — 10% chance by Nov 3

Growing season257 daysfrost-free, median

A hard freeze (28 °F) usually ends around February 21 and returns around December 2.

From the NOAA station Hammond 5 E, LA — 5 miles away, elevation 36 ft. NOAA NCEI U.S. Climate Normals 1991–2020, 32 °F threshold. Low spots and valleys can freeze later in spring than the station.

When to plant vegetables in 70401

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Jan 25 – Feb 8

SpinachSow outdoors · Jan 25 – Feb 15

Broccoli, cabbageStart indoors · Dec 28 – Jan 11

Broccoli, cabbageTransplant · Feb 15 – Mar 1

Onion setsPlant outdoors · Feb 8 – Feb 22

PotatoesPlant outdoors · Feb 15 – Mar 1

LettuceSow outdoors · Feb 8 – Feb 22

Carrots, beetsSow outdoors · Feb 15 – Mar 1

TomatoesStart indoors · Jan 11 – Jan 25

TomatoesTransplant · Mar 15 – Mar 29

Peppers, eggplantStart indoors · Dec 28 – Jan 11

Peppers, eggplantTransplant · Mar 22 – Apr 5

BeansSow outdoors · Mar 15 – Mar 29

Sweet cornSow outdoors · Mar 15 – Mar 29

Cucumbers, squashSow outdoors · Mar 15 – Mar 29

Fall lettuce, spinachSow outdoors · Sep 24 – Oct 8

GarlicPlant cloves · Nov 5 – Dec 10

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 8) and first fall frost (Nov 19) with the rules of thumb U.S. extension services publish. Cool-season crops take a light frost; warm-season crops do best once the soil is above about 60 °F.

When spring arrived in 2026

In 2026, spring leaf-out near 70401 came on Jan 11 — 15 days earlier than the 1991–2020 average (Jan 26).

average
Jan 262026
Jan 11

JanFebMarAprMayJun

The Spring Index marks the day when accumulated warmth is enough for lilac and honeysuckle to leaf out — a widely used signal that the growing season has started. Source: USA National Phenology Network, www.usanpn.org — Spring Indices, first leaf, 2026 (data as of 2026-09-08) and 30-year average 1991–2020 (CC BY 4.0).

Native plants for zone 9a in Louisiana

517 plants native to the lower 48 states, recorded in Louisiana, and rated by the USDA to survive 20 °F or colder — the bottom of zone 9a. Each links to its USDA PLANTS profile.

Source: USDA, NRCS. 2026. The PLANTS Database (plants.usda.gov), National Plant Data Team — state distribution, native status and the “Temperature, Minimum” characteristic. Check light, moisture and soil needs before buying; local nurseries and your state native plant society can confirm what thrives in Hammond, LA.

Soil in Hammond, LA

The soil mapped at the center of ZIP 70401 is Guyton — silt loam, poorly drained.

TextureSilt loama good balance for most vegetables

pH4.8strongly acidic; most vegetables like 6.0–7.0

DrainagePoorly drainedconsider raised beds

Organic matter2.25%moderate

Hydrologic groupC/Dslow when drained; wet otherwise

Farmland classprime farmlandUSDA classification

Map unit: Guyton silt loam, 0 to 1 percent slopes, rarely flooded.

Soil Survey Staff, Natural Resources Conservation Service, USDA. Soil Survey Geographic (SSURGO) Database, via Soil Data Access, accessed 2026-10-29. The soil at the center point of ZIP 70401; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Hammond, LA

Summer high92 °Faverage high, July

Winter low38 °Faverage low, January

Hot days86days a year at 90 °F or more

Freezing nights31nights a year at 32 °F or less

Growing degree days6,460base 50 °F — the season’s usable heat

Longest day14 h 07 mindaylight on June 21

Shortest day10 h 10 mindaylight on December 21

Onions to growShort-daysummer days stay under about 14 h 20 min, so long-day varieties won’t bulb

Precipitation62.2 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Hammond 5 E, LA (5 mi away); precipitation: Hammond, LA (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 9a.

Independence, LA · 8 mi

All 4 ZIP codes in Hammond → · Louisiana planting zones →

Questions about 70401

What planting zone is ZIP code 70401?

ZIP code 70401 (Hammond, LA) is in USDA hardiness zone 9a on the 2023 map: the coldest night of an average winter reaches 20 to 25 °F (−6.7 to −3.9 °C).

When is the last frost in Hammond, LA?

The median last spring frost (32 °F) near 70401 is March 8; after March 31 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Hammond 5 E station.

When is the first frost in Hammond, LA?

The median first fall frost near 70401 is November 19, giving a median frost-free growing season of 257 days.

When should I plant tomatoes in 70401?

Start tomato seeds indoors around Jan 11 – Jan 25 and set transplants outside around Mar 15 – Mar 29, one to three weeks after the median last frost.

How much rain and snow does 70401 get?

About 62.2 inches of precipitation a year (NOAA 1991–2020 normals, Hammond station).

How hot do summers get in Hammond, LA?

The average high peaks at 92 °F in July, with about 86 days a year at 90 °F or more.

What kind of soil does 70401 have?

The USDA soil survey maps Guyton at the center of ZIP 70401: silt loam, poorly drained, pH about 4.8 (strongly acidic).

Did spring come early in Hammond, LA in 2026?

Spring leaf-out near 70401 came on Jan 11 in 2026, 15 days earlier than the 1991–2020 average (Jan 26), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Hammond, LA?

Short-day onions: the longest day near 70401 is 14 h 07 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.

Did the zone for 70401 change?

Yes. The 2012 USDA map put 70401 in zone 8b; the 2023 map puts it in zone 9a. The newer map uses 1991–2020 data and more weather stations.