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

Planting zone for 97861 — Mikkalo, OR

ZIP code 97861 (Mikkalo, Gilliam County) is in USDA zone 7b: the coldest winter night averages 5 to 10 °F. The median last spring frost is May 10 and the first fall frost October 7.

Where ZIP 97861 is

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.

Zone7b5 to 10 °F
Coldest night−15 to −12.2 °C
Last frostMay 10
First frostOct 7
2012 zone7b

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 7b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Mikkalo, OR…

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 Mikkalo, OR

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 10median — 50% chance of a later frost
Safe for tender plantsMay 27only 10% chance of frost after
First fall frostOctober 7median — 10% chance by Sep 21
Growing season148 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 25 and returns around October 24.

From the NOAA station Condon, OR — 14 miles away, elevation 2,881 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 97861

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 29 – Apr 12
SpinachSow outdoors · Mar 29 – Apr 19
Broccoli, cabbageStart indoors · Mar 1 – Mar 15
Broccoli, cabbageTransplant · Apr 19 – May 3
Onion setsPlant outdoors · Apr 12 – Apr 26
PotatoesPlant outdoors · Apr 19 – May 3
LettuceSow outdoors · Apr 12 – Apr 26
Carrots, beetsSow outdoors · Apr 19 – May 3
TomatoesStart indoors · Mar 15 – Mar 29
TomatoesTransplant · May 17 – May 31
Peppers, eggplantStart indoors · Mar 1 – Mar 15
Peppers, eggplantTransplant · May 24 – Jun 7
BeansSow outdoors · May 17 – May 31
Sweet cornSow outdoors · May 17 – May 31
Cucumbers, squashSow outdoors · May 17 – May 31
Fall lettuce, spinachSow outdoors · Aug 12 – Aug 26
GarlicPlant cloves · Sep 23 – Oct 28
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 10) and first fall frost (Oct 7) 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 97861 came on Mar 8 — 8 days earlier than the 1991–2020 average (Mar 16).

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 7b in Oregon

627 plants native to the lower 48 states, recorded in Oregon, and rated by the USDA to survive 5 °F or colder — the bottom of zone 7b. Each links to its USDA PLANTS profile.

Trees 40

Alaska cedar75 ft · blooms mid spring · low shade tolerance · to −22 °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 °FBrewer spruce100 ft · blooms early summer · low shade tolerance · to −13 °F

Shrubs 120

alderleaf buckthorn3 ft · blooms late spring · low shade tolerance · to −33 °Falderleaf mountain mahogany15 ft · blooms late spring · medium shade tolerance · to −41 °Falpine laurel1 ft · blooms late spring · low shade tolerance · to −28 °Fantelope bitterbrush6 ft · blooms early spring · medium shade tolerance · to −36 °Fbeaked hazelnut15 ft · blooms early spring · low shade tolerance · to −47 °Fbig sagebrush4 ft · blooms mid summer · 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 164

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 2

riverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °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 Mikkalo, OR.

Soil in Mikkalo, OR

The soil mapped at the center of ZIP 97861 is Ritzville — silt loam, well drained.

TextureSilt loama good balance for most vegetables
pH7.2neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter1.5%low — add compost
Hydrologic groupBwater soaks in moderately
Farmland classPrime farmland if irrigatedUSDA classification

Map unit: Ritzville silt loam, 2 to 7 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 97861; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Mikkalo, OR

Summer high84 °Faverage high, July
Winter low25 °Faverage low, December
Hot days17days a year at 90 °F or more
Freezing nights139nights a year at 32 °F or less
Growing degree days2,067base 50 °F — the season’s usable heat
Longest day15 h 41 mindaylight on June 21
Shortest day8 h 42 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation14.1 inper year, rain and melted snow
Snowfall26 inper year

Average high and low, by month

10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 40 °F, low 26 °F 40°26° JanFebruary: average high 44 °F, low 27 °F 44°27° FebMarch: average high 52 °F, low 31 °F 52°31° MarApril: average high 58 °F, low 35 °F 58°35° AprMay: average high 67 °F, low 42 °F 67°42° MayJune: average high 73 °F, low 47 °F 73°47° JunJuly: average high 84 °F, low 53 °F 84°53° JulAugust: average high 84 °F, low 52 °F 84°52° AugSeptember: average high 75 °F, low 46 °F 75°46° SepOctober: average high 61 °F, low 37 °F 61°37° OctNovember: average high 48 °F, low 31 °F 48°31° NovDecember: average high 39 °F, low 25 °F 39°25° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″January: 1.81 in precipitation, 5.6 in snowfall 1.8❄6 JanFebruary: 1.26 in precipitation, 4.7 in snowfall 1.3❄5 FebMarch: 1.20 in precipitation, 2 in snowfall 1.2❄2 MarApril: 1.30 in precipitation, 1 in snowfall 1.3❄1 AprMay: 1.65 in precipitation 1.6 MayJune: 1.11 in precipitation 1.1 JunJuly: 0.39 in precipitation 0.4 JulAugust: 0.38 in precipitation 0.4 AugSeptember: 0.47 in precipitation 0.5 SepOctober: 1.17 in precipitation, 0.2 in snowfall 1.2 OctNovember: 1.51 in precipitation, 1.7 in snowfall 1.5❄2 NovDecember: 1.82 in precipitation, 10.3 in snowfall 1.8❄10 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Condon, OR (14 mi away); precipitation: Condon, OR (14 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.

978127b
Arlington, OR · 10 mi
978237a
Condon, OR · 13 mi
978437b
Ione, OR · 16 mi
970397a
Moro, OR · 20 mi
970657b
Wasco, OR · 24 mi
970337a
Kent, OR · 25 mi
993567a
Roosevelt, WA · 28 mi
978397a
Lexington, OR · 30 mi

Oregon planting zones →

Questions about 97861

What planting zone is ZIP code 97861?

ZIP code 97861 (Mikkalo, OR) is in USDA hardiness zone 7b on the 2023 map: the coldest night of an average winter reaches 5 to 10 °F (−15 to −12.2 °C).

When is the last frost in Mikkalo, OR?

The median last spring frost (32 °F) near 97861 is May 10; after May 27 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Condon station.

When is the first frost in Mikkalo, OR?

The median first fall frost near 97861 is October 7, giving a median frost-free growing season of 148 days.

When should I plant tomatoes in 97861?

Start tomato seeds indoors around Mar 15 – Mar 29 and set transplants outside around May 17 – May 31, one to three weeks after the median last frost.

How much rain and snow does 97861 get?

About 14.1 inches of precipitation a year and 26 inches of snowfall (NOAA 1991–2020 normals, Condon station).

How hot do summers get in Mikkalo, OR?

The average high peaks at 84 °F in July, with about 17 days a year at 90 °F or more.

What kind of soil does 97861 have?

The USDA soil survey maps Ritzville at the center of ZIP 97861: silt loam, well drained, pH about 7.2 (neutral).

Did spring come early in Mikkalo, OR in 2026?

Spring leaf-out near 97861 came on Mar 8 in 2026, 8 days earlier than the 1991–2020 average (Mar 16), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Mikkalo, OR?

Long-day onions: the longest day near 97861 is 15 h 41 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).