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

Planting zone for 98556 — Littlerock, WA

ZIP code 98556 (Littlerock, Thurston County) is in USDA zone 8a: the coldest winter night averages 10 to 15 °F. The median last spring frost is April 29 and the first fall frost October 14.

Where ZIP 98556 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 frostApr 29
First frostOct 14
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 Littlerock, 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 Littlerock, WA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 29median — 50% chance of a later frost
Safe for tender plantsMay 15only 10% chance of frost after
First fall frostOctober 14median — 10% chance by Sep 28
Growing season169 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 5 and returns around November 1.

From the NOAA station Olympia Airport, WA — 13 miles away, elevation 187 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 98556

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 18 – Apr 1
SpinachSow outdoors · Mar 18 – Apr 8
Broccoli, cabbageStart indoors · Feb 18 – Mar 4
Broccoli, cabbageTransplant · Apr 8 – Apr 22
Onion setsPlant outdoors · Apr 1 – Apr 15
PotatoesPlant outdoors · Apr 8 – Apr 22
LettuceSow outdoors · Apr 1 – Apr 15
Carrots, beetsSow outdoors · Apr 8 – Apr 22
TomatoesStart indoors · Mar 4 – Mar 18
TomatoesTransplant · May 6 – May 20
Peppers, eggplantStart indoors · Feb 18 – Mar 4
Peppers, eggplantTransplant · May 13 – May 27
BeansSow outdoors · May 6 – May 20
Sweet cornSow outdoors · May 6 – May 20
Cucumbers, squashSow outdoors · May 6 – May 20
Fall lettuce, spinachSow outdoors · Aug 19 – Sep 2
GarlicPlant cloves · Sep 30 – Nov 4
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 29) and first fall frost (Oct 14) 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 98556 came on Feb 23 — 7 days earlier than the 1991–2020 average (Mar 2).

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 Littlerock, WA

The soil mapped at the center of ZIP 98556 is Olympic — silt loam, well drained.

TextureSilt loama good balance for most vegetables
pH5.5moderately acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter5.5%high
Hydrologic groupCwater soaks in slowly
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Olympic silt loam, 5 to 20 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 98556; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Littlerock, WA

Summer high78 °Faverage high, July
Winter low32 °Faverage low, February
Hot days6days a year at 90 °F or more
Freezing nights77nights a year at 32 °F or less
Growing degree days1,723base 50 °F — the season’s usable heat
Longest day15 h 53 mindaylight on June 21
Shortest day8 h 31 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation69.9 inper year, rain and melted snow

Average high and low, by month

20°30°40°50°60°70°80°90°32 °FJanuary: average high 46 °F, low 33 °F 46°33° JanFebruary: average high 49 °F, low 32 °F 49°32° FebMarch: average high 54 °F, low 35 °F 54°35° MarApril: average high 59 °F, low 38 °F 59°38° AprMay: average high 66 °F, low 43 °F 66°43° MayJune: average high 71 °F, low 47 °F 71°47° JunJuly: average high 78 °F, low 51 °F 78°51° JulAugust: average high 78 °F, low 51 °F 78°51° AugSeptember: average high 72 °F, low 46 °F 72°46° SepOctober: average high 60 °F, low 41 °F 60°41° OctNovember: average high 51 °F, low 36 °F 51°36° NovDecember: average high 45 °F, low 33 °F 45°33° Dec

Precipitation by month inches

0″2″4″6″8″10″12″January: 12.09 in precipitation 12.1 JanFebruary: 6.69 in precipitation 6.7 FebMarch: 8.29 in precipitation 8.3 MarApril: 5.10 in precipitation 5.1 AprMay: 2.85 in precipitation 2.9 MayJune: 1.83 in precipitation 1.8 JunJuly: 0.72 in precipitation 0.7 JulAugust: 1.12 in precipitation 1.1 AugSeptember: 2.61 in precipitation 2.6 SepOctober: 6.45 in precipitation 6.5 OctNovember: 10.82 in precipitation 10.8 NovDecember: 11.35 in precipitation 11.3 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Olympia Airport, WA (13 mi away); precipitation: Olympia 6.5 Sw, WA (9 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

985128a
Olympia, WA · 6 mi
985798b
Rochester, WA · 7 mi
985118a
Tumwater, WA · 7 mi
985688a
Oakville, WA · 8 mi
985598b
Malone, WA · 10 mi
985448b
Galvin, WA · 11 mi
985578a
Mccleary, WA · 12 mi
985308b
Bucoda, WA · 14 mi

Washington planting zones →

Questions about 98556

What planting zone is ZIP code 98556?

ZIP code 98556 (Littlerock, 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 Littlerock, WA?

The median last spring frost (32 °F) near 98556 is April 29; after May 15 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Olympia Airport station.

When is the first frost in Littlerock, WA?

The median first fall frost near 98556 is October 14, giving a median frost-free growing season of 169 days.

When should I plant tomatoes in 98556?

Start tomato seeds indoors around Mar 4 – Mar 18 and set transplants outside around May 6 – May 20, one to three weeks after the median last frost.

How much rain and snow does 98556 get?

About 69.9 inches of precipitation a year (NOAA 1991–2020 normals, Olympia 6.5 Sw station).

How hot do summers get in Littlerock, WA?

The average high peaks at 78 °F in July, with about 6 days a year at 90 °F or more.

What kind of soil does 98556 have?

The USDA soil survey maps Olympic at the center of ZIP 98556: silt loam, well drained, pH about 5.5 (moderately acidic).

Did spring come early in Littlerock, WA in 2026?

Spring leaf-out near 98556 came on Feb 23 in 2026, 7 days earlier than the 1991–2020 average (Mar 2), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Littlerock, WA?

Long-day onions: the longest day near 98556 is 15 h 53 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).