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

Planting zone for 97735 — Fort Rock, OR

ZIP code 97735 (Fort Rock, Lake County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is June 8 and the first fall frost September 15.

Where ZIP 97735 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.

Zone6a−10 to −5 °F

Coldest night−23.3 to −20.6 °C

Last frostJun 8

First frostSep 15

2012 zone5b

Was 5b 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 6a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Fort Rock, 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 Fort Rock, OR

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostJune 8median — 50% chance of a later frost

Safe for tender plantsJune 25only 10% chance of frost after

First fall frostSeptember 15median — 10% chance by Aug 31

Growing season96 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 18 and returns around September 29.

From the NOAA station Summer Lake 1 S, OR — 32 miles away, elevation 4,193 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 97735

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Apr 27 – May 11

SpinachSow outdoors · Apr 27 – May 18

Broccoli, cabbageStart indoors · Mar 30 – Apr 13

Broccoli, cabbageTransplant · May 18 – Jun 1

Onion setsPlant outdoors · May 11 – May 25

PotatoesPlant outdoors · May 18 – Jun 1

LettuceSow outdoors · May 11 – May 25

Carrots, beetsSow outdoors · May 18 – Jun 1

TomatoesStart indoors · Apr 13 – Apr 27

TomatoesTransplant · Jun 15 – Jun 29

Peppers, eggplantStart indoors · Mar 30 – Apr 13

Peppers, eggplantTransplant · Jun 22 – Jul 6

BeansSow outdoors · Jun 15 – Jun 29

Sweet cornSow outdoors · Jun 15 – Jun 29

Cucumbers, squashSow outdoors · Jun 15 – Jun 29

Fall lettuce, spinachSow outdoors · Jul 21 – Aug 4

GarlicPlant cloves · Sep 1 – Oct 6

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Jun 8) and first fall frost (Sep 15) 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 97735 came on Mar 20 — 20 days earlier than the 1991–2020 average (Apr 9).

average
Apr 92026
Mar 20

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 6a in Oregon

607 plants native to the lower 48 states, recorded in Oregon, and rated by the USDA to survive −10 °F or colder — the bottom of zone 6a. 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 Fort Rock, OR.

Soil in Fort Rock, OR

The soil mapped at the center of ZIP 97735 is Bonnick — very gravelly ashy loamy coarse sand, somewhat excessively drained.

TextureVery gravelly ashy loamy coarse sanddrains and warms fast; dries out and needs more feeding

pH7.4slightly alkaline; most vegetables like 6.0–7.0

DrainageSomewhat excessively drainednatural drainage class

Organic matter2%moderate

Hydrologic groupAwater soaks in fast

Farmland classFarmland of statewide importanceUSDA classification

Map unit: Bonnick-Fort Rock complex, 1 to 8 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 97735; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Fort Rock, OR

Summer high85 °Faverage high, July

Winter low18 °Faverage low, December

Hot days24days a year at 90 °F or more

Freezing nights211nights a year at 32 °F or less

Growing degree days1,414base 50 °F — the season’s usable heat

Longest day15 h 25 mindaylight on June 21

Shortest day8 h 57 mindaylight on December 21

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

Precipitation11.2 inper year, rain and melted snow

Snowfall7 inper year; 2 days with snow on the ground

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: The Poplars, OR (9 mi away); precipitation: The Poplars, OR (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.

976386a

Silver Lake, OR · 17 mi

976416a

Christmas Valley, OR · 24 mi

977396b

La Pine, OR · 32 mi

976406b

Summer Lake, OR · 36 mi

Oregon planting zones →

Questions about 97735

What planting zone is ZIP code 97735?

ZIP code 97735 (Fort Rock, OR) is in USDA hardiness zone 6a on the 2023 map: the coldest night of an average winter reaches −10 to −5 °F (−23.3 to −20.6 °C).

When is the last frost in Fort Rock, OR?

The median last spring frost (32 °F) near 97735 is June 8; after June 25 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Summer Lake 1 S station.

When is the first frost in Fort Rock, OR?

The median first fall frost near 97735 is September 15, giving a median frost-free growing season of 96 days.

When should I plant tomatoes in 97735?

Start tomato seeds indoors around Apr 13 – Apr 27 and set transplants outside around Jun 15 – Jun 29, one to three weeks after the median last frost.

How much rain and snow does 97735 get?

About 11.2 inches of precipitation a year and 7 inches of snowfall (NOAA 1991–2020 normals, The Poplars station).

How hot do summers get in Fort Rock, OR?

The average high peaks at 85 °F in July, with about 24 days a year at 90 °F or more.

What kind of soil does 97735 have?

The USDA soil survey maps Bonnick at the center of ZIP 97735: very gravelly ashy loamy coarse sand, somewhat excessively drained, pH about 7.4 (slightly alkaline).

Did spring come early in Fort Rock, OR in 2026?

Spring leaf-out near 97735 came on Mar 20 in 2026, 20 days earlier than the 1991–2020 average (Apr 9), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Fort Rock, OR?

Long-day onions: the longest day near 97735 is 15 h 25 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 97735 change?

Yes. The 2012 USDA map put 97735 in zone 5b; the 2023 map puts it in zone 6a. The newer map uses 1991–2020 data and more weather stations.