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

Planting zone for 98310 — Bremerton, WA

ZIP code 98310 (Bremerton, Kitsap County) is in USDA zone 8b: the coldest winter night averages 15 to 20 °F. The median last spring frost is March 29 and the first fall frost November 14.

Where ZIP 98310 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 frostMar 29
First frostNov 14
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 Bremerton, 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 Bremerton, WA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMarch 29median — 50% chance of a later frost
Safe for tender plantsApril 24only 10% chance of frost after
First fall frostNovember 14median — 10% chance by Oct 26
Growing season227 daysfrost-free, median

A hard freeze (28 °F) usually ends around February 27 and returns around November 30.

From the NOAA station Bremerton, WA — 3 miles away, elevation 112 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 98310

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Feb 15 – Mar 1
SpinachSow outdoors · Feb 15 – Mar 8
Broccoli, cabbageStart indoors · Jan 18 – Feb 1
Broccoli, cabbageTransplant · Mar 8 – Mar 22
Onion setsPlant outdoors · Mar 1 – Mar 15
PotatoesPlant outdoors · Mar 8 – Mar 22
LettuceSow outdoors · Mar 1 – Mar 15
Carrots, beetsSow outdoors · Mar 8 – Mar 22
TomatoesStart indoors · Feb 1 – Feb 15
TomatoesTransplant · Apr 5 – Apr 19
Peppers, eggplantStart indoors · Jan 18 – Feb 1
Peppers, eggplantTransplant · Apr 12 – Apr 26
BeansSow outdoors · Apr 5 – Apr 19
Sweet cornSow outdoors · Apr 5 – Apr 19
Cucumbers, squashSow outdoors · Apr 5 – Apr 19
Fall lettuce, spinachSow outdoors · Sep 19 – Oct 3
GarlicPlant cloves · Oct 31 – Dec 5
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 29) and first fall frost (Nov 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 98310 came on Feb 8 — 14 days earlier than the 1991–2020 average (Feb 22).

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.

Trees 32

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 114

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 293

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 Bremerton, WA.

Soil in Bremerton, WA

The soil mapped at the center of ZIP 98310 is Kitsap — ashy silt loam, moderately well drained.

TextureAshy silt loama good balance for most vegetables
pH5.8moderately acidic; most vegetables like 6.0–7.0
DrainageModerately well drainednatural drainage class
Organic matter6.5%high
Hydrologic groupCwater soaks in slowly
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Kitsap silt loam, 15 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 98310; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Bremerton, WA

Summer high77 °Faverage high, July
Winter low35 °Faverage low, February
Hot days4days a year at 90 °F or more
Freezing nights42nights a year at 32 °F or less
Growing degree days2,058base 50 °F — the season’s usable heat
Longest day15 h 59 mindaylight on June 21
Shortest day8 h 25 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation45.2 inper year, rain and melted snow

Average high and low, by month

20°30°40°50°60°70°80°90°32 °FJanuary: average high 47 °F, low 36 °F 47°36° JanFebruary: average high 49 °F, low 35 °F 49°35° FebMarch: average high 54 °F, low 38 °F 54°38° MarApril: average high 59 °F, low 41 °F 59°41° AprMay: average high 66 °F, low 47 °F 66°47° MayJune: average high 70 °F, low 51 °F 70°51° JunJuly: average high 77 °F, low 55 °F 77°55° JulAugust: average high 77 °F, low 55 °F 77°55° AugSeptember: average high 72 °F, low 51 °F 72°51° SepOctober: average high 61 °F, low 45 °F 61°45° OctNovember: average high 51 °F, low 39 °F 51°39° NovDecember: average high 46 °F, low 35 °F 46°35° Dec

Precipitation by month inches

0″2″4″6″8″January: 7.08 in precipitation 7.1 JanFebruary: 3.83 in precipitation 3.8 FebMarch: 5.22 in precipitation 5.2 MarApril: 3.25 in precipitation 3.3 AprMay: 2.34 in precipitation 2.3 MayJune: 1.44 in precipitation 1.4 JunJuly: 0.70 in precipitation 0.7 JulAugust: 0.98 in precipitation 1.0 AugSeptember: 1.66 in precipitation 1.7 SepOctober: 4.15 in precipitation 4.2 OctNovember: 7.27 in precipitation 7.3 NovDecember: 7.26 in precipitation 7.3 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Bremerton, WA (3 mi away); precipitation: Bremerton 1.8 Ne, WA (within 1 mile). Daylight is calculated from latitude.

Nearby ZIP codes

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

983379a
Bremerton, WA · 2 mi
983119a
Bremerton, WA · 3 mi
983939a
Tracyton, WA · 3 mi
983789a
Retsil, WA · 3 mi
983669a
Port Orchard, WA · 4 mi
981109a
Bainbridge Island, WA · 6 mi
983849a
South Colby, WA · 6 mi
980619a
Rollingbay, WA · 7 mi

All 4 ZIP codes in Bremerton → · Washington planting zones →

Questions about 98310

What planting zone is ZIP code 98310?

ZIP code 98310 (Bremerton, 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 Bremerton, WA?

The median last spring frost (32 °F) near 98310 is March 29; after April 24 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Bremerton station.

When is the first frost in Bremerton, WA?

The median first fall frost near 98310 is November 14, giving a median frost-free growing season of 227 days.

When should I plant tomatoes in 98310?

Start tomato seeds indoors around Feb 1 – Feb 15 and set transplants outside around Apr 5 – Apr 19, one to three weeks after the median last frost.

How much rain and snow does 98310 get?

About 45.2 inches of precipitation a year (NOAA 1991–2020 normals, Bremerton 1.8 Ne station).

How hot do summers get in Bremerton, WA?

The average high peaks at 77 °F in July, with about 4 days a year at 90 °F or more.

What kind of soil does 98310 have?

The USDA soil survey maps Kitsap at the center of ZIP 98310: ashy silt loam, moderately well drained, pH about 5.8 (moderately acidic).

Did spring come early in Bremerton, WA in 2026?

Spring leaf-out near 98310 came on Feb 8 in 2026, 14 days earlier than the 1991–2020 average (Feb 22), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Bremerton, WA?

Long-day onions: the longest day near 98310 is 15 h 59 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).