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

Planting zone for 98355 — Mineral, WA

ZIP code 98355 (Mineral, Lewis County) is in USDA zone 8a: the coldest winter night averages 10 to 15 °F. The median last spring frost is May 22 and the first fall frost October 3.

Where ZIP 98355 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.

Zone8a10 to 15 °F
Coldest night−12.2 to −9.4 °C
Last frostMay 22
First frostOct 3
2012 zone8a

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 8a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Mineral, 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 Mineral, WA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 22median — 50% chance of a later frost
Safe for tender plantsJune 9only 10% chance of frost after
First fall frostOctober 3median — 10% chance by Sep 16
Growing season134 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 2 and returns around October 20.

From the NOAA station Longmire Rainier Nps, WA — 11 miles away, elevation 2,763 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 98355

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Apr 10 – Apr 24
SpinachSow outdoors · Apr 10 – May 1
Broccoli, cabbageStart indoors · Mar 13 – Mar 27
Broccoli, cabbageTransplant · May 1 – May 15
Onion setsPlant outdoors · Apr 24 – May 8
PotatoesPlant outdoors · May 1 – May 15
LettuceSow outdoors · Apr 24 – May 8
Carrots, beetsSow outdoors · May 1 – May 15
TomatoesStart indoors · Mar 27 – Apr 10
TomatoesTransplant · May 29 – Jun 12
Peppers, eggplantStart indoors · Mar 13 – Mar 27
Peppers, eggplantTransplant · Jun 5 – Jun 19
BeansSow outdoors · May 29 – Jun 12
Sweet cornSow outdoors · May 29 – Jun 12
Cucumbers, squashSow outdoors · May 29 – Jun 12
Fall lettuce, spinachSow outdoors · Aug 8 – Aug 22
GarlicPlant cloves · Sep 19 – Oct 24
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 22) and first fall frost (Oct 3) 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 98355 came on Mar 22 — 24 days earlier than the 1991–2020 average (Apr 15).

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 8a in Washington

611 plants native to the lower 48 states, recorded in Washington, and rated by the USDA to survive 10 °F or colder — the bottom of zone 8a. Each links to its USDA PLANTS profile.

Trees 31

Alaska cedar75 ft · blooms mid spring · low shade tolerance · to −22 °FAmerican sycamore100 ft · blooms spring · medium shade tolerance · to −34 °Fbalsam poplar80 ft · blooms late spring · high shade tolerance · to −79 °Fbigleaf maple60 ft · blooms mid spring · medium shade tolerance · to −14 °Fblack locust60 ft · blooms spring · high shade tolerance · to −37 °Fboxelder60 ft · blooms early spring · low shade tolerance · to −46 °F

Shrubs 113

alderleaf buckthorn3 ft · blooms late spring · low shade tolerance · to −33 °FAllegheny serviceberry35 ft · blooms early spring · low shade tolerance · to −38 °Falpine laurel1 ft · blooms late spring · low shade tolerance · to −28 °FAmerican plum24 ft · blooms mid spring · high shade tolerance · to −38 °Fantelope bitterbrush6 ft · blooms early spring · medium shade tolerance · to −36 °FBarclay's willow15 ft · high shade tolerance · to −43 °F

Wildflowers & perennials 292

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °Falpine bistort1 ft · blooms mid spring · high shade tolerance · to −38 °Falpine mountainsorrel1 ft · blooms mid summer · medium shade tolerance · to −43 °FAmerican alpine speedwell1 ft · blooms summer · medium shade tolerance · to −28 °FAmerican bistort1.5 ft · blooms mid spring · high shade tolerance · to −38 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °F

Grasses 157

Alaska brome5 ft · blooms late spring · low shade tolerance · to −18 °FAlaska oniongrass3 ft · blooms mid spring · low shade tolerance · to −33 °Falkali cordgrass3 ft · blooms late summer · high shade tolerance · to −38 °Falkali sacaton3 ft · blooms mid summer · high shade tolerance · to −38 °Falpine timothy1.4 ft · blooms late spring · medium shade tolerance · to −43 °FAmerican beachgrass2.5 ft · blooms spring · high shade tolerance · to −28 °F

Vines 3

riverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °Ftrumpet creeper2 ft · blooms summer · high shade tolerance · to −13 °Fwestern white clematis1 ft · blooms mid summer · medium shade tolerance · to −38 °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 Mineral, WA.

Soil in Mineral, WA

The soil mapped at the center of ZIP 98355 is Cattcreek — gravelly sandy loam, well drained.

TextureGravelly sandy loamdrains and warms fast; dries out and needs more feeding
pH6.1slightly acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter5.5%high
Hydrologic groupBwater soaks in moderately
Farmland classNot prime farmlandUSDA classification

Map unit: Cattcreek cindery sandy loam, till substratum, 8 to 30 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 98355; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Mineral, WA

Summer high76 °Faverage high, August
Winter low25 °Faverage low, December
Hot days6days a year at 90 °F or more
Freezing nights157nights a year at 32 °F or less
Growing degree days1,132base 50 °F — the season’s usable heat
Longest day15 h 51 mindaylight on June 21
Shortest day8 h 33 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation81.6 inper year, rain and melted snow

Average high and low, by month

10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 37 °F, low 26 °F 37°26° JanFebruary: average high 40 °F, low 26 °F 40°26° FebMarch: average high 45 °F, low 28 °F 45°28° MarApril: average high 51 °F, low 31 °F 51°31° AprMay: average high 60 °F, low 37 °F 60°37° MayJune: average high 66 °F, low 42 °F 66°42° JunJuly: average high 75 °F, low 46 °F 75°46° JulAugust: average high 76 °F, low 46 °F 76°46° AugSeptember: average high 69 °F, low 42 °F 69°42° SepOctober: average high 55 °F, low 35 °F 55°35° OctNovember: average high 43 °F, low 29 °F 43°29° NovDecember: average high 36 °F, low 25 °F 36°25° Dec

Precipitation by month inches

0″2″4″6″8″10″12″January: 12.07 in precipitation 12.1 JanFebruary: 10.05 in precipitation 10.1 FebMarch: 9.65 in precipitation 9.7 MarApril: 6.54 in precipitation 6.5 AprMay: 4.32 in precipitation 4.3 MayJune: 3.04 in precipitation 3.0 JunJuly: 0.99 in precipitation 1.0 JulAugust: 1.38 in precipitation 1.4 AugSeptember: 2.98 in precipitation 3.0 SepOctober: 6.95 in precipitation 7.0 OctNovember: 11.61 in precipitation 11.6 NovDecember: 12.02 in precipitation 12.0 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Longmire Rainier Nps, WA (11 mi away); precipitation: Mineral 0.2 S, WA (7 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

983308a
Elbe, WA · 7 mi
983368a
Glenoma, WA · 8 mi
983977b
Longmire, WA · 11 mi
983288b
Eatonville, WA · 12 mi
983568b
Morton, WA · 14 mi
983488b
La Grande, WA · 16 mi
983778a
Randle, WA · 17 mi
985338b
Cinebar, WA · 17 mi

Washington planting zones →

Questions about 98355

What planting zone is ZIP code 98355?

ZIP code 98355 (Mineral, WA) is in USDA hardiness zone 8a on the 2023 map: the coldest night of an average winter reaches 10 to 15 °F (−12.2 to −9.4 °C).

When is the last frost in Mineral, WA?

The median last spring frost (32 °F) near 98355 is May 22; after June 9 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Longmire Rainier Nps station.

When is the first frost in Mineral, WA?

The median first fall frost near 98355 is October 3, giving a median frost-free growing season of 134 days.

When should I plant tomatoes in 98355?

Start tomato seeds indoors around Mar 27 – Apr 10 and set transplants outside around May 29 – Jun 12, one to three weeks after the median last frost.

How much rain and snow does 98355 get?

About 81.6 inches of precipitation a year (NOAA 1991–2020 normals, Mineral 0.2 S station).

How hot do summers get in Mineral, WA?

The average high peaks at 76 °F in August, with about 6 days a year at 90 °F or more.

What kind of soil does 98355 have?

The USDA soil survey maps Cattcreek at the center of ZIP 98355: gravelly sandy loam, well drained, pH about 6.1 (slightly acidic).

Did spring come early in Mineral, WA in 2026?

Spring leaf-out near 98355 came on Mar 22 in 2026, 24 days earlier than the 1991–2020 average (Apr 15), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Mineral, WA?

Long-day onions: the longest day near 98355 is 15 h 51 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).