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

Planting zone for 98250 — Friday Harbor, WA

ZIP code 98250 (Friday Harbor, San Juan County) is in USDA zone 9a: the coldest winter night averages 20 to 25 °F. The median last spring frost is March 26 and the first fall frost November 10.

Where ZIP 98250 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.

Zone9a20 to 25 °F

Coldest night−6.7 to −3.9 °C

Last frostMar 26

First frostNov 10

2012 zone8b

Was 8b on the 2012 map — half a zone warmer now. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 9a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Friday Harbor, 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 Friday Harbor, WA

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMarch 26median — 50% chance of a later frost

Safe for tender plantsApril 21only 10% chance of frost after

First fall frostNovember 10median — 10% chance by Oct 21

Growing season230 daysfrost-free, median

A hard freeze (28 °F) usually ends around February 22 and returns around December 1.

From the NOAA station Friday Harbor Airport, WA — 4 miles away, elevation 108 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 98250

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Feb 12 – Feb 26

SpinachSow outdoors · Feb 12 – Mar 5

Broccoli, cabbageStart indoors · Jan 15 – Jan 29

Broccoli, cabbageTransplant · Mar 5 – Mar 19

Onion setsPlant outdoors · Feb 26 – Mar 12

PotatoesPlant outdoors · Mar 5 – Mar 19

LettuceSow outdoors · Feb 26 – Mar 12

Carrots, beetsSow outdoors · Mar 5 – Mar 19

TomatoesStart indoors · Jan 29 – Feb 12

TomatoesTransplant · Apr 2 – Apr 16

Peppers, eggplantStart indoors · Jan 15 – Jan 29

Peppers, eggplantTransplant · Apr 9 – Apr 23

BeansSow outdoors · Apr 2 – Apr 16

Sweet cornSow outdoors · Apr 2 – Apr 16

Cucumbers, squashSow outdoors · Apr 2 – Apr 16

Fall lettuce, spinachSow outdoors · Sep 15 – Sep 29

GarlicPlant cloves · Oct 27 – Dec 1

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 26) and first fall frost (Nov 10) 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 98250 came on Feb 11 — 12 days earlier than the 1991–2020 average (Feb 23).

average
Feb 232026
Feb 11

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 9a in Washington

617 plants native to the lower 48 states, recorded in Washington, and rated by the USDA to survive 20 °F or colder — the bottom of zone 9a. 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 Friday Harbor, WA.

Soil in Friday Harbor, WA

The soil mapped at the center of ZIP 98250 is Deadmanbay — slightly decomposed plant material, somewhat poorly drained.

TextureSlightly decomposed plant materialtop layer

pH5.5moderately acidic; most vegetables like 6.0–7.0

DrainageSomewhat poorly drainedconsider raised beds

Organic matter75%high

Hydrologic groupC/Dslow when drained; wet otherwise

Farmland classprime farmlandUSDA classification

Map unit: Deadmanbay-Morancreek complex, 2 to 15 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 98250; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Friday Harbor, WA

Summer high73 °Faverage high, August

Winter low37 °Faverage low, January

Hot days1days a year at 90 °F or more

Freezing nights40nights a year at 32 °F or less

Growing degree days1,470base 50 °F — the season’s usable heat

Longest day16 h 08 mindaylight on June 21

Shortest day8 h 17 mindaylight on December 21

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

Precipitation27.3 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: Friday Harbor Airport, WA (4 mi away); precipitation: Friday Harbor 2.6 Wnw, WA (within 1 mile). Daylight is calculated from latitude.

Nearby ZIP codes

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

982439a

Deer Harbor, WA · 6 mi

982869a

Shaw Island, WA · 6 mi

982809a

Orcas, WA · 10 mi

982619a

Lopez Island, WA · 10 mi

982979a

Waldron, WA · 11 mi

982459a

Eastsound, WA · 11 mi

982229a

Blakely Island, WA · 12 mi

982798b

Olga, WA · 13 mi

Washington planting zones →

Questions about 98250

What planting zone is ZIP code 98250?

ZIP code 98250 (Friday Harbor, WA) is in USDA hardiness zone 9a on the 2023 map: the coldest night of an average winter reaches 20 to 25 °F (−6.7 to −3.9 °C).

When is the last frost in Friday Harbor, WA?

The median last spring frost (32 °F) near 98250 is March 26; after April 21 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Friday Harbor Airport station.

When is the first frost in Friday Harbor, WA?

The median first fall frost near 98250 is November 10, giving a median frost-free growing season of 230 days.

When should I plant tomatoes in 98250?

Start tomato seeds indoors around Jan 29 – Feb 12 and set transplants outside around Apr 2 – Apr 16, one to three weeks after the median last frost.

How much rain and snow does 98250 get?

About 27.3 inches of precipitation a year (NOAA 1991–2020 normals, Friday Harbor 2.6 Wnw station).

How hot do summers get in Friday Harbor, WA?

The average high peaks at 73 °F in August, with about 1 days a year at 90 °F or more.

What kind of soil does 98250 have?

The USDA soil survey maps Deadmanbay at the center of ZIP 98250: slightly decomposed plant material, somewhat poorly drained, pH about 5.5 (moderately acidic).

Did spring come early in Friday Harbor, WA in 2026?

Spring leaf-out near 98250 came on Feb 11 in 2026, 12 days earlier than the 1991–2020 average (Feb 23), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Friday Harbor, WA?

Long-day onions: the longest day near 98250 is 16 h 08 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 98250 change?

Yes. The 2012 USDA map put 98250 in zone 8b; the 2023 map puts it in zone 9a. The newer map uses 1991–2020 data and more weather stations.