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

Planting zone for 00544 — Holtsville, NY

ZIP code 00544 (Holtsville, Suffolk County) is in USDA zone 7b: the coldest winter night averages 5 to 10 °F. The median last spring frost is April 10 and the first fall frost November 2.

Where ZIP 00544 is

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.

Zone7b5 to 10 °F
Coldest night−15 to −12.2 °C
Last frostApr 10
First frostNov 2
2012 zone—

The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 7b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Holtsville, NY…

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 Holtsville, NY

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 10median — 50% chance of a later frost
Safe for tender plantsApril 25only 10% chance of frost after
First fall frostNovember 2median — 10% chance by Oct 18
Growing season207 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 30 and returns around November 14.

From the NOAA station Islip Li Macarthur Airport, NY — 3 miles away, elevation 85 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 00544

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Feb 27 – Mar 13
SpinachSow outdoors · Feb 27 – Mar 20
Broccoli, cabbageStart indoors · Jan 30 – Feb 13
Broccoli, cabbageTransplant · Mar 20 – Apr 3
Onion setsPlant outdoors · Mar 13 – Mar 27
PotatoesPlant outdoors · Mar 20 – Apr 3
LettuceSow outdoors · Mar 13 – Mar 27
Carrots, beetsSow outdoors · Mar 20 – Apr 3
TomatoesStart indoors · Feb 13 – Feb 27
TomatoesTransplant · Apr 17 – May 1
Peppers, eggplantStart indoors · Jan 30 – Feb 13
Peppers, eggplantTransplant · Apr 24 – May 8
BeansSow outdoors · Apr 17 – May 1
Sweet cornSow outdoors · Apr 17 – May 1
Cucumbers, squashSow outdoors · Apr 17 – May 1
Fall lettuce, spinachSow outdoors · Sep 7 – Sep 21
GarlicPlant cloves · Oct 19 – Nov 23
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 10) and first fall frost (Nov 2) 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 00544 came on Mar 31 — about the same time as the 1991–2020 average (Mar 29).

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 7b in New York

660 plants native to the lower 48 states, recorded in New York, and rated by the USDA to survive 5 °F or colder — the bottom of zone 7b. Each links to its USDA PLANTS profile.

Trees 78

American basswood100 ft · blooms late spring · low shade tolerance · to −46 °FAmerican beech80 ft · blooms mid spring · low shade tolerance · to −44 °FAmerican chestnut115 ft · blooms early summer · high shade tolerance · to −33 °FAmerican elm120 ft · blooms early spring · medium shade tolerance · to −46 °FAmerican sycamore100 ft · blooms spring · medium shade tolerance · to −34 °Farborvitae50 ft · blooms mid spring · medium shade tolerance · to −33 °F

Shrubs 131

alderleaf buckthorn3 ft · blooms late spring · low shade tolerance · to −33 °FAllegheny serviceberry35 ft · blooms early spring · low shade tolerance · to −38 °Falternateleaf dogwood25 ft · blooms mid spring · low shade tolerance · to −47 °FAmerican black currant3 ft · blooms early spring · to −46 °FAmerican hazelnut10 ft · blooms spring · medium shade tolerance · to −33 °FAmerican holly40 ft · blooms mid spring · low shade tolerance · to −20 °F

Wildflowers & perennials 224

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °FAmerican bur-reed3 ft · blooms indeterminate · medium shade tolerance · to −33 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °FAmerican licorice4 ft · blooms late spring · medium shade tolerance · to −38 °FAmerican lotus3 ft · blooms mid summer · high shade tolerance · to −36 °FAmerican pokeweed7 ft · blooms mid summer · low shade tolerance · to −33 °F

Grasses 201

alkali sacaton3 ft · blooms mid summer · high shade tolerance · to −38 °FAmerican beachgrass2.5 ft · blooms spring · high shade tolerance · to −28 °Farctic brome3 ft · blooms early summer · low shade tolerance · to −33 °FAtlantic mannagrass3 ft · blooms summer · low shade tolerance · to −8 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °FBailey's sedge2.1 ft · blooms late spring · low shade tolerance · to −33 °F

Vines 9

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °FAmerican wisteria50 ft · blooms spring · low shade tolerance · to −3 °Fdevil's darning needles15 ft · blooms mid summer · medium shade tolerance · to −38 °Ffrost grape83 ft · blooms late spring · medium shade tolerance · to −23 °Friverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °Fsummer grape30 ft · blooms late spring · low shade tolerance · to −23 °F

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 Holtsville, NY.

Soil in Holtsville, NY

The soil mapped at the center of ZIP 00544 is Riverhead — sandy loam, well drained.

TextureSandy loamdrains and warms fast; dries out and needs more feeding
pH5.2strongly acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter3%moderate
Hydrologic groupAwater soaks in fast
Farmland classprime farmlandUSDA classification

Map unit: Riverhead sandy loam, 0 to 3 percent slopes.

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 00544; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Holtsville, NY

Summer high83 °Faverage high, July
Winter low25 °Faverage low, January
Hot days8days a year at 90 °F or more
Freezing nights98nights a year at 32 °F or less
Growing degree days3,242base 50 °F — the season’s usable heat
Longest day15 h 06 mindaylight on June 21
Shortest day9 h 14 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation46 inper year, rain and melted snow
Snowfall32 inper year; 23 days with snow on the ground

Average high and low, by month

10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 39 °F, low 25 °F 39°25° JanFebruary: average high 41 °F, low 26 °F 41°26° FebMarch: average high 48 °F, low 32 °F 48°32° MarApril: average high 58 °F, low 41 °F 58°41° AprMay: average high 68 °F, low 51 °F 68°51° MayJune: average high 77 °F, low 61 °F 77°61° JunJuly: average high 83 °F, low 67 °F 83°67° JulAugust: average high 81 °F, low 66 °F 81°66° AugSeptember: average high 75 °F, low 59 °F 75°59° SepOctober: average high 64 °F, low 47 °F 64°47° OctNovember: average high 54 °F, low 38 °F 54°38° NovDecember: average high 44 °F, low 30 °F 44°30° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″January: 3.66 in precipitation, 10.3 in snowfall 3.7❄10 JanFebruary: 3.29 in precipitation, 9.4 in snowfall 3.3❄9 FebMarch: 4.51 in precipitation, 6.5 in snowfall 4.5❄7 MarApril: 4.06 in precipitation, 0.6 in snowfall 4.1❄1 AprMay: 3.28 in precipitation 3.3 MayJune: 4.00 in precipitation 4.0 JunJuly: 3.26 in precipitation 3.3 JulAugust: 4.24 in precipitation 4.2 AugSeptember: 3.60 in precipitation 3.6 SepOctober: 3.97 in precipitation 4.0 OctNovember: 3.41 in precipitation, 0.5 in snowfall 3.4❄1 NovDecember: 4.71 in precipitation, 4.5 in snowfall 4.7❄5 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Islip Li Macarthur Airport, NY (3 mi away); precipitation: Islip Li Macarthur Airport, NY (3 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

1 of the 8 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

005017b
Holtsville, NY · <1 mi
117427b
Holtsville, NY · <1 mi
117387b
Farmingville, NY · 2 mi
117417b
Holbrook, NY · 2 mi
117637a
Medford, NY · 3 mi
117797b
Ronkonkoma, NY · 4 mi
117847b
Selden, NY · 4 mi
117207b
Centereach, NY · 4 mi

All 3 ZIP codes in Holtsville → · New York planting zones →

Questions about 00544

What planting zone is ZIP code 00544?

ZIP code 00544 (Holtsville, NY) is in USDA hardiness zone 7b on the 2023 map: the coldest night of an average winter reaches 5 to 10 °F (−15 to −12.2 °C).

When is the last frost in Holtsville, NY?

The median last spring frost (32 °F) near 00544 is April 10; after April 25 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Islip Li Macarthur Airport station.

When is the first frost in Holtsville, NY?

The median first fall frost near 00544 is November 2, giving a median frost-free growing season of 207 days.

When should I plant tomatoes in 00544?

Start tomato seeds indoors around Feb 13 – Feb 27 and set transplants outside around Apr 17 – May 1, one to three weeks after the median last frost.

How much rain and snow does 00544 get?

About 46 inches of precipitation a year and 32 inches of snowfall (NOAA 1991–2020 normals, Islip Li Macarthur Airport station).

How hot do summers get in Holtsville, NY?

The average high peaks at 83 °F in July, with about 8 days a year at 90 °F or more.

What kind of soil does 00544 have?

The USDA soil survey maps Riverhead at the center of ZIP 00544: sandy loam, well drained, pH about 5.2 (strongly acidic).

Did spring come early in Holtsville, NY in 2026?

Spring leaf-out near 00544 came on Mar 31 in 2026, about the same as the 1991–2020 average (Mar 29), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Holtsville, NY?

Long-day onions: the longest day near 00544 is 15 h 06 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).