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

Planting zone for 13621 — Chase Mills, NY

ZIP code 13621 (Chase Mills, St. Lawrence County) is in USDA zone 4b: the coldest winter night averages −25 to −20 °F. The median last spring frost is May 8 and the first fall frost October 1.

Where ZIP 13621 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.

Zone4b−25 to −20 °F

Coldest night−31.7 to −28.9 °C

Last frostMay 8

First frostOct 1

2012 zone4b

Same zone as on the 2012 map. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 4b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Chase Mills, 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 Chase Mills, NY

JanFebMarAprMayJunJulAugSepOctNovDec

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

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

Safe for tender plantsMay 23only 10% chance of frost after

First fall frostOctober 1median — 10% chance by Sep 17

Growing season144 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 28 and returns around October 13.

From the NOAA station Massena Intl Airport, NY — 12 miles away, elevation 213 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 13621

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 27 – Apr 10

SpinachSow outdoors · Mar 27 – Apr 17

Broccoli, cabbageStart indoors · Feb 27 – Mar 13

Broccoli, cabbageTransplant · Apr 17 – May 1

Onion setsPlant outdoors · Apr 10 – Apr 24

PotatoesPlant outdoors · Apr 17 – May 1

LettuceSow outdoors · Apr 10 – Apr 24

Carrots, beetsSow outdoors · Apr 17 – May 1

TomatoesStart indoors · Mar 13 – Mar 27

TomatoesTransplant · May 15 – May 29

Peppers, eggplantStart indoors · Feb 27 – Mar 13

Peppers, eggplantTransplant · May 22 – Jun 5

BeansSow outdoors · May 15 – May 29

Sweet cornSow outdoors · May 15 – May 29

Cucumbers, squashSow outdoors · May 15 – May 29

Fall lettuce, spinachSow outdoors · Aug 6 – Aug 20

GarlicPlant cloves · Sep 17 – Oct 22

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 8) and first fall frost (Oct 1) 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 13621 came on Apr 16 — 4 days earlier than the 1991–2020 average (Apr 20).

average
Apr 202026
Apr 16

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).

Soil in Chase Mills, NY

The soil mapped at the center of ZIP 13621 is Adams — loamy fine sand, somewhat excessively drained.

TextureLoamy fine sanddrains and warms fast; dries out and needs more feeding

pH5.2strongly acidic; most vegetables like 6.0–7.0

DrainageSomewhat excessively drainednatural drainage class

Organic matter3.5%moderate

Hydrologic groupAwater soaks in fast

Farmland classFarmland of statewide importanceUSDA classification

Map unit: Adams loamy fine sand, 2 to 8 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 13621; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Chase Mills, NY

Summer high81 °Faverage high, July

Winter low6 °Faverage low, January

Hot days6days a year at 90 °F or more

Freezing nights158nights a year at 32 °F or less

Growing degree days2,229base 50 °F — the season’s usable heat

Longest day15 h 36 mindaylight on June 21

Shortest day8 h 47 mindaylight on December 21

Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)

Precipitation39 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: Massena Intl Airport, NY (12 mi away); precipitation: Norfolk, NY (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 4b.

136674b

Norfolk, NY · 3 mi

136784b

Raymondville, NY · 5 mi

136944b

Waddington, NY · 6 mi

New York planting zones →

Questions about 13621

What planting zone is ZIP code 13621?

ZIP code 13621 (Chase Mills, NY) is in USDA hardiness zone 4b on the 2023 map: the coldest night of an average winter reaches −25 to −20 °F (−31.7 to −28.9 °C).

When is the last frost in Chase Mills, NY?

The median last spring frost (32 °F) near 13621 is May 8; after May 23 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Massena Intl Airport station.

When is the first frost in Chase Mills, NY?

The median first fall frost near 13621 is October 1, giving a median frost-free growing season of 144 days.

When should I plant tomatoes in 13621?

Start tomato seeds indoors around Mar 13 – Mar 27 and set transplants outside around May 15 – May 29, one to three weeks after the median last frost.

How much rain and snow does 13621 get?

About 39 inches of precipitation a year (NOAA 1991–2020 normals, Norfolk station).

How hot do summers get in Chase Mills, NY?

The average high peaks at 81 °F in July, with about 6 days a year at 90 °F or more.

What kind of soil does 13621 have?

The USDA soil survey maps Adams at the center of ZIP 13621: loamy fine sand, somewhat excessively drained, pH about 5.2 (strongly acidic).

Did spring come early in Chase Mills, NY in 2026?

Spring leaf-out near 13621 came on Apr 16 in 2026, 4 days earlier than the 1991–2020 average (Apr 20), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Chase Mills, NY?

Long-day onions: the longest day near 13621 is 15 h 36 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).