Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 30, 2026

Planting zone for Pasco, WA

Pasco, WA is in USDA zones 7a to 7b across its 2 ZIP codes. The median last spring frost is April 30 and the first fall frost October 13.

Pasco on the zone map

Outlined: its 1 ZIP code areas · 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.

Zones7a–7b0 to 10 °F

ZIP codes2

Last frostApr 30

First frostOct 13

Growing season166 days

7a 1 ZIP 7b 1 ZIP

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Pasco, 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 Pasco, WA

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 30median — 50% chance of a later frost

Safe for tender plantsMay 16only 10% chance of frost after

First fall frostOctober 13median — 10% chance by Sep 29

Growing season166 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 13 and returns around October 23.

From the NOAA station Sagemoor, WA, elevation 594 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 Pasco

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 19 – Apr 2

SpinachSow outdoors · Mar 19 – Apr 9

Broccoli, cabbageStart indoors · Feb 19 – Mar 5

Broccoli, cabbageTransplant · Apr 9 – Apr 23

Onion setsPlant outdoors · Apr 2 – Apr 16

PotatoesPlant outdoors · Apr 9 – Apr 23

LettuceSow outdoors · Apr 2 – Apr 16

Carrots, beetsSow outdoors · Apr 9 – Apr 23

TomatoesStart indoors · Mar 5 – Mar 19

TomatoesTransplant · May 7 – May 21

Peppers, eggplantStart indoors · Feb 19 – Mar 5

Peppers, eggplantTransplant · May 14 – May 28

BeansSow outdoors · May 7 – May 21

Sweet cornSow outdoors · May 7 – May 21

Cucumbers, squashSow outdoors · May 7 – May 21

Fall lettuce, spinachSow outdoors · Aug 18 – Sep 1

GarlicPlant cloves · Sep 29 – Nov 3

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 30) and first fall frost (Oct 13) 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 99301 came on Mar 6 — 4 days earlier than the 1991–2020 average (Mar 10).

average
Mar 102026
Mar 6

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 7a in Washington

590 plants native to the lower 48 states, recorded in Washington, and rated by the USDA to survive 0 °F or colder — the bottom of zone 7a. 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 Pasco, WA.

Soil in Pasco, WA

The soil mapped at the center of ZIP 99301 is Quincy — loamy fine sand, excessively drained.

TextureLoamy fine sanddrains and warms fast; dries out and needs more feeding

pH7.3neutral; most vegetables like 6.0–7.0

DrainageExcessively drainednatural drainage class

Organic matter0.75%low — add compost

Hydrologic groupAwater soaks in fast

Farmland classFarmland of statewide importanceUSDA classification

Map unit: Quincy-Hezel complex, 0 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 99301; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Pasco, WA

Summer high90 °Faverage high, July

Winter low25 °Faverage low, January

Hot days43days a year at 90 °F or more

Freezing nights127nights a year at 32 °F or less

Growing degree days2,773base 50 °F — the season’s usable heat

Longest day15 h 48 mindaylight on June 21

Shortest day8 h 36 mindaylight on December 21

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

Precipitation9.8 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: Sagemoor, WA (6 mi away); precipitation: Sagemoor, WA (6 mi away). Daylight is calculated from latitude.

ZIP codes in Pasco

Washington planting zones →

Questions about Pasco

What planting zone is Pasco, WA?

Pasco, WA is in USDA hardiness zones 7a to 7b on the 2023 map (7a: 0 to 5 °F; 7b: 5 to 10 °F).

When is the last frost in Pasco, WA?

The median last spring frost is April 30 and the median first fall frost is October 13 (NOAA 1991–2020 normals, Sagemoor station).

When can I plant a garden in Pasco, WA?

Cool-season crops like peas and spinach go in around Mar 19 – Apr 9; tomatoes, peppers, beans and squash after about May 7, once frost risk has passed.

What kind of onions grow in Pasco, WA?

Long-day onions: the longest day is 15 h 48 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

How much rain and snow does Pasco, WA get?

About 9.8 inches of precipitation a year (NOAA 1991–2020 normals).