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

Planting zone for 98294 — Sultan, WA

ZIP code 98294 (Sultan, Snohomish County) is in USDA zone 8b: the coldest winter night averages 15 to 20 °F. The median last spring frost is April 15 and the first fall frost October 25.

Where ZIP 98294 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.

Zone8b15 to 20 °F

Coldest night−9.4 to −6.7 °C

Last frostApr 15

First frostOct 25

2012 zone8b

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 8b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Sultan, WA…

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 Sultan, WA

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 15median — 50% chance of a later frost

Safe for tender plantsMay 7only 10% chance of frost after

First fall frostOctober 25median — 10% chance by Oct 5

Growing season192 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 18 and returns around November 12.

From the NOAA station Startup 1 E, WA — 3 miles away, elevation 171 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 98294

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 4 – Mar 18

SpinachSow outdoors · Mar 4 – Mar 25

Broccoli, cabbageStart indoors · Feb 4 – Feb 18

Broccoli, cabbageTransplant · Mar 25 – Apr 8

Onion setsPlant outdoors · Mar 18 – Apr 1

PotatoesPlant outdoors · Mar 25 – Apr 8

LettuceSow outdoors · Mar 18 – Apr 1

Carrots, beetsSow outdoors · Mar 25 – Apr 8

TomatoesStart indoors · Feb 18 – Mar 4

TomatoesTransplant · Apr 22 – May 6

Peppers, eggplantStart indoors · Feb 4 – Feb 18

Peppers, eggplantTransplant · Apr 29 – May 13

BeansSow outdoors · Apr 22 – May 6

Sweet cornSow outdoors · Apr 22 – May 6

Cucumbers, squashSow outdoors · Apr 22 – May 6

Fall lettuce, spinachSow outdoors · Aug 30 – Sep 13

GarlicPlant cloves · Oct 11 – Nov 15

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 15) and first fall frost (Oct 25) 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 98294 came on Feb 21 — 13 days earlier than the 1991–2020 average (Mar 6).

average
Mar 62026
Feb 21

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 8b in Washington

614 plants native to the lower 48 states, recorded in Washington, and rated by the USDA to survive 15 °F or colder — the bottom of zone 8b. 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 Sultan, WA.

Soil in Sultan, WA

The soil mapped at the center of ZIP 98294 is Tokul — gravelly medial loam, moderately well drained.

TextureGravelly medial loama good balance for most vegetables

pH5.8moderately acidic; most vegetables like 6.0–7.0

DrainageModerately well drainednatural drainage class

Organic matter12.5%high

Hydrologic groupCwater soaks in slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Tokul-Ogarty-Rock outcrop complex, 25 to 65 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 98294; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Sultan, WA

Summer high78 °Faverage high, July

Winter low34 °Faverage low, January

Hot days5days a year at 90 °F or more

Freezing nights53nights a year at 32 °F or less

Growing degree days1,904base 50 °F — the season’s usable heat

Longest day16 h 01 mindaylight on June 21

Shortest day8 h 23 mindaylight on December 21

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

Precipitation68.3 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: Startup 1 E, WA (3 mi away); precipitation: Startup 1 E, WA (3 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

Carnation, WA · 10 mi

Snohomish, WA · 13 mi

982918b

Snohomish, WA · 14 mi

Washington planting zones →

Questions about 98294

What planting zone is ZIP code 98294?

ZIP code 98294 (Sultan, WA) is in USDA hardiness zone 8b on the 2023 map: the coldest night of an average winter reaches 15 to 20 °F (−9.4 to −6.7 °C).

When is the last frost in Sultan, WA?

The median last spring frost (32 °F) near 98294 is April 15; after May 7 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Startup 1 E station.

When is the first frost in Sultan, WA?

The median first fall frost near 98294 is October 25, giving a median frost-free growing season of 192 days.

When should I plant tomatoes in 98294?

Start tomato seeds indoors around Feb 18 – Mar 4 and set transplants outside around Apr 22 – May 6, one to three weeks after the median last frost.

How much rain and snow does 98294 get?

About 68.3 inches of precipitation a year (NOAA 1991–2020 normals, Startup 1 E station).

How hot do summers get in Sultan, WA?

The average high peaks at 78 °F in July, with about 5 days a year at 90 °F or more.

What kind of soil does 98294 have?

The USDA soil survey maps Tokul at the center of ZIP 98294: gravelly medial loam, moderately well drained, pH about 5.8 (moderately acidic).

Did spring come early in Sultan, WA in 2026?

Spring leaf-out near 98294 came on Feb 21 in 2026, 13 days earlier than the 1991–2020 average (Mar 6), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Sultan, WA?

Long-day onions: the longest day near 98294 is 16 h 01 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).