What does USDA hardiness zone 4a mean in New York?

Zone 4a means an average annual extreme minimum winter temperature of −30 to −25 °F — the standard USDA measure of which perennials survive winter. 10 locations in New York fall in this zone. It does not set planting dates; see the frost calendar below for that.

Where in New York's zone 4a is the growing season longest?

Lyon Mountain runs the longest season on this page at about 151 days; Saranac Lake is shortest at about 97 days — they share the same hardiness zone, but they sit at different weather stations, so their frost calendars differ.

When should I plant tomatoes in New York's zone 4a?

Using Cranberry Lake's frost dates (this page's median-season location): start seeds indoors about Mar 23 – Apr 6, then transplant outside about May 25 – Jun 1. Your own location in the table above may differ by a week or two — use the ZIP planner on the home page for your exact station's dates.

Does every location in New York's zone 4a have the same frost dates?

No — they do not all share a weather station, so frost dates vary by a week or more across the 10 locations listed (see the table above for each location's own dates).

USDA zone 4a in New York

−30 to −25 °F avg. annual extreme minimum · 10 locations in this group · NOAA 1991–2020 normals

USDA plant hardiness zone 4a covers 10 locations across New York (average annual extreme minimum −30 to −25 °F): Cranberry Lake, NY, Cranberry Lake, NY, Eagle Bay, NY, Long Lake, NY, Long Lake, NY, Lyon Mountain, NY, and 4 more. Average last spring frost across this group ranges May 6 (Lyon Mountain) to June 2 (Saranac Lake), and growing seasons run 97–151 days (Saranac Lake to Lyon Mountain) — even within one state, because hardiness sets winter survival, not planting dates. The table below gives every New York location's own frost dates; the printable planting calendar uses Cranberry Lake, this group's median-season location.

USDA zone: 4a−30 to −25 °F
Last frost range: May 6–Jun 2avg, 32°F
First frost range: Sep 9–Oct 4avg, 32°F
Growing season range: 97–151days

Locations in this group

Every location below shares this zone and a nearby weather station, but keeps its own frost dates — find your town for its own numbers, or use the ZIP planner on the home page for an instant personalized answer.

Own frost dates per location.
Location	Also covers	Nearest station	Last frost	First frost	Season (days)
Cranberry Lake	Colton	Canton 4 Se	May 9	Sep 30	142
Cranberry Lake *	Star Lake	Wanakena Rngr School	May 18	Sep 28	132
Eagle Bay	—	Big Moose 3 Se	May 21	Sep 24	127
Long Lake	—	Indian Lake 2sw	May 23	Sep 27	125
Long Lake	—	Newcomb	May 21	Sep 26	126
Lyon Mountain	—	Malone	May 6	Oct 4	151
Parishville	Tupper Lake	Tupper Lake Sunmount	May 16	Sep 28	134
Saranac Lake	St. Regis Falls, Paul Smiths	Saranac Rgnl Ap	Jun 2	Sep 9	97
Saranac Lake	Lake Placid	Lake Placid 2 S	May 27	Sep 22	118
Thendara	—	Old Forge	May 18	Sep 30	134

* Cranberry Lake is this group's median-season location — the calendar below is computed from its data.

Data: NOAA NCEI U.S. Climate Normals 1991–2020 (public domain) and USDA Plant Hardiness Zone Map 2023. Planting windows synthesized from U.S. Cooperative Extension guides.

Planting calendar (Cranberry Lake, representative)

Computed from Cranberry Lake's average frost dates — the median-season location in this New Yorkzone 4a group. hatched = start seeds indoors, solid green = plant out, teal = a fall sowing, and the terracotta dot marks the estimated first harvest. Ranges are extension-guide planning guidance, not guarantees — your own location's dates may run a week or two earlier or later (see the table above).

Crop

JanFebMarAprMayJunJulAugSepOctNovDec

Tomato

Pepper

Cucumber

Summer squash / zucchini

Start indoors
Plant out
Fall sowing
First harvest

Planting windows for Cranberry Lake (New York, zone 4a), this group's representative location.
Crop	Frost tolerance	Start indoors	Plant out	First harvest	Fall planting	Season fit
Tomato	Tender	Mar 23 – Apr 6	May 25 – Jun 1	Jul 24 – Aug 13	—	matures comfortably
Pepper	Very tender	Mar 9 – Mar 23	Jun 1 – Jun 8	Jul 31 – Aug 30	—	matures comfortably
Cucumber	Tender	Apr 20 – Apr 27	May 25 – Jun 1	Jul 14 – Aug 3	—	matures comfortably
Summer squash / zucchini	Tender	—	May 25 – Jun 1	Jul 9 – Jul 24	—	matures comfortably
Bush bean	Tender	—	May 25 – Jun 1	Jul 14 – Jul 24	Jul 30 – Aug 9	matures comfortably
Sweet corn	Tender	—	May 18 – Jun 1	Jul 17 – Aug 16	—	matures comfortably
Basil	Very tender	Apr 6 – Apr 20	May 25 – Jun 1	Jun 24 – Jul 9	—	matures comfortably
Lettuce	Half-hardy	Apr 6 – Apr 20	Apr 20 – May 4	Jun 4 – Jun 19	Jul 16 – Jul 31	matures comfortably
Pea	Hardy	—	Apr 6 – Apr 20	May 31 – Jun 15	Jul 6 – Jul 21	matures comfortably
Spinach	Hardy	—	Apr 6 – Apr 20	May 16 – May 26	Jul 26 – Aug 5	matures comfortably
Carrot	Half-hardy	—	Apr 27 – May 4	Jun 26 – Jul 16	Jun 26 – Jul 16	matures comfortably
Broccoli	Half-hardy	Mar 23 – Apr 6	Apr 20 – May 4	Jun 14 – Jul 4	Jul 1 – Jul 21	matures comfortably

Which crops fit this growing season

Using Cranberry Lake's own 132-day growing season (32°F, NOAA 1991–2020 median) against each crop's real days-to-maturity range: 12 of 12 crops mature here with comfortable margin. A different location in the table above with a longer or shorter season will get a different mix — the ZIP planner on the home page gives your own.

Frost & freeze dates (Cranberry Lake)

From NOAA's 1991–2020 Climate Normals at station USC00308944. The median (p50) is the average date; the 90%-safe column is the date the freeze has passed in about 9 years out of 10 — the conservative date to plant after or harvest before.

Freeze probabilities by temperature threshold (MM/DD, NOAA 1991–2020), Cranberry Lake.
Threshold	Last spring — avg	Last spring — 90%-safe	First fall — avg	First fall — 90%-safe	Season (days)
36°F	May 31	Jun 14	Sep 15	Oct 1	109
32°F (freeze)	May 18	Jun 2	Sep 28	Oct 10	132
28°F	May 6	May 23	Oct 8	Oct 25	156
24°F	Apr 25	May 13	Oct 23	Nov 5	179

Growing degree days

Growing degree days (GDD) accumulate warmth above a base temperature over the year — a better predictor of crop development than the calendar alone. This group's median GDD (base 50°F) across all 10 locations is 1,715; Cranberry Lake's own reading is shown below.

Annual growing degree days for Cranberry Lake (°F·days, NOAA 1991–2020).
Model	°F·days	Used for
Base 50°F (warm-season)	2,005	standard warm-season base (tomato, corn, beans)
Base 40°F (cool-season)	3,821	cool-season crops (brassicas, greens)

Hardiness zone 4a in New York

Zone 4a means an average annual extreme minimum winter temperature of about −30 to −25 °F on the USDA's 2023 map — the number that tells you which perennials, shrubs, and trees reliably survive an average winter here. It does not set your planting dates, which come from the frost calendar above. New York spans 8 hardiness zones in this dataset — see all New York locations for the full range, including zones4b, 5a, 5b, 6a, 6b, 7a, 7b.

Explore zone 4a in other states at zone 4a, or see all USDA hardiness zones.

Frequently asked questions

What does USDA hardiness zone 4a mean in New York?: Zone 4a means an average annual extreme minimum winter temperature of −30 to −25 °F — the standard USDA measure of which perennials survive winter. 10 locations in New York fall in this zone. It does not set planting dates; see the frost calendar below for that.
Where in New York's zone 4a is the growing season longest?: Lyon Mountain runs the longest season on this page at about 151 days; Saranac Lake is shortest at about 97 days — they share the same hardiness zone, but they sit at different weather stations, so their frost calendars differ.
When should I plant tomatoes in New York's zone 4a?: Using Cranberry Lake's frost dates (this page's median-season location): start seeds indoors about Mar 23 – Apr 6, then transplant outside about May 25 – Jun 1. Your own location in the table above may differ by a week or two — use the ZIP planner on the home page for your exact station's dates.
Does every location in New York's zone 4a have the same frost dates?: No — they do not all share a weather station, so frost dates vary by a week or more across the 10 locations listed (see the table above for each location's own dates).

Sources & method

Frost, freeze, growing-season, and growing-degree-day figures are NOAA NCEI U.S. Climate Normals 1991–2020, one reading per location's own nearest station (see the table above). The hardiness zone is the USDA Plant Hardiness Zone Map 2023, matched to each location's ZIP. Planting windows are computed by counting from the average last and first frost using per-crop offsets synthesized from U.S. Cooperative Extension guides — the full method and citations are on the methodology page.