Fruit Trees for Klamath Falls, Altamont, Merrill and Keno, Oregon

In the January 1962 cold snap, the Klamath Falls airport station out at Kingsley Field, 6 miles south of downtown, read −25°F, while the old Klamath Falls station 2 miles south-southwest of downtown read −14°F. That 11°F gap over 5 miles of flat ground is what picking fruit trees for Klamath Falls, Altamont, Merrill and Keno comes down to: where the cold settles on a still night, and how far above it you can get.

This map covers the Klamath Basin of south-central Oregon, high desert in the Cascade rain shadow, from the south half of Upper Klamath Lake to Tulelake and Dorris just over the California line, with Keno, Merrill, Malin, Bonanza and the lake's east shore in between. By our standards it's mild winter country, and most of what we sell clears it. Spring is the hard part. Type your address in the box on the map to get the number for your own place, and the list of what we sell that has come through it.

How to read this map

Each spot gets a 30-year planning low, the number our cold hardiness calculator gives plus a light adjustment for the ground around you: a safe number to plan a tree around, not a record. The MFTC zone puts it in half zones, and the typical winter is an average year's coldest night. The spring layer tells you how many degrees warmer or colder a spot runs than downtown Klamath Falls on a still, clear night in bloom.

Downtown Klamath Falls plans for −13°F, MFTC zone 5b, with a typical winter of 3°F. The middle of the growing ground plans for −19°F (zone 5a), and the middle half falls between −21°F and −16°F. The warm end is the city and its slopes: Stewart Lenox at −11°F, the Oregon Institute of Technology (OIT) hill at −12°F, Fairhaven and Altamont at −13°F. The cold end is the Lost River country and the old lake beds, where Merrill and Malin plan for −20°F, Keno and Bonanza −21°F and Tulelake −22°F, and the Sprague River valley, where Sprague River plans for −27°F, zone 4a, the coldest of any named place we checked.

Why the map looks the way it does

Nearly all the farm ground here is the bottom of an old lake. Lake Modoc once ran about 75 miles, with a high stand near 4,239 feet, and the Klamath Hills, Miller Hill and Turkey Hill stood up out of it as islands. Today's floor sits at about 4,035 to 4,155 feet, close to dead level, ringed by ridges and mountains of 5,000 to 6,000 feet. On a clear, still night it gives its heat up to a dry sky, cold off the ridges slides down to join it, and not much moves it out. Oregon's Department of Environmental Quality (DEQ), which tracks the town's winter smoke, describes very strong, shallow night inversions, and arctic air that often comes down Upper Klamath Lake into the basin and holds temperatures well below freezing for weeks.

The lowest, most closed-in ground is the south end. The Tule Lake sump sits at 4,035 feet, and the Lost River had no natural outlet; it just ended in Tule Lake. A closed basin fills with cold air up to its lowest notch before any spills out. NOAA station records show the Tulelake station running a median 7°F colder than the old Klamath Falls station over 51 years, and in the December 1932 cold snap Tulelake read −27°F to the old station's −10°F.

The Klamath River drains the basin through a narrow door. Below Lake Ewauna it meanders 18 miles through drained marsh to Keno Dam, then runs fast through a narrow canyon in Cascade volcanic rock. Cold air backs up above a narrows, and Keno sits at the head of this one, 8°F colder than downtown on the map.

Height above the floor buys warmth because the inversions are strong and shallow. In the December 2013 cold snap the Swan Lake Mountain station, at 6,830 feet north of town, read 13°F while the Klamath Falls airport and Ag stations read −20°F, a 33°F difference with the warm air on top. Benches and lower slopes that rise out of the pool get some of that; Stewart Lenox, on a bench 150 feet up, has the warmest number of any town or neighborhood we checked.

The city is the other warm spot, right on the floor. Downtown plans 4°F to 5°F warmer than the map gives the airport and Ag station sites, and the old Klamath Falls station, which kept records from 1901 to 1997, ran a median 3°F warmer than both. Towns hold heat on still nights, the older downtown sits over geothermal springs with district heating and private wells, and the Link River outlet stays open when the rest of the lake freezes. We haven't found a published measurement of how much any of that adds.

The lake doesn't do what a big lake does elsewhere. Upper Klamath Lake is Oregon's largest freshwater lake, about 96 square miles, but its mean depth is 14 feet, and shallow water freezes early and stops giving off heat in midwinter. Snowfall drops off to about 26 inches a year at Malin and 23 at Tulelake, so the floor that plans coldest also has the thinnest blanket over the roots.

The spring frost layer follows the same drainage at full strength, so it spreads wider. On a still bloom night Fairhaven and the OIT hill run 8°F warmer than downtown and the slopes of Miller Hill 14°F warmer, while Algoma and Shady Pine on the east shore run 5°F colder, the coldest spring readings of any town or hamlet we checked. Mountaintops turn cold again: the top of Hogback Mountain, 1,910 feet over the floor, reads 2°F colder than downtown, while Moyina Heights on its lower slope reads 5°F warmer.

Downtown Klamath Falls and the hills above town

Klamath Falls started in 1867 as Linkville, on the Link River, which runs 1.5 miles from the lake's outlet to Lake Ewauna. Downtown sits at 4,108 feet and plans for −13°F, MFTC zone 5b, with a typical winter of 3°F. Within 3 miles the floor runs −14°F, the benches −11°F and the warmest tenth of the ground −10°F. OSU Extension says Klamath Falls yards with geothermal heat underground may succeed with plants that struggle on the higher outskirts of town, and the Hot Springs neighborhood's name points to the same water.

The best fruit ground is up the slopes. Southwest of downtown, Stewart Lenox sits on a bench at 4,235 feet, plans for −11°F with a typical winter of 5°F, and runs 6°F warmer than downtown at bloom. Fairhaven, on the hillside next to it, plans for −13°F and runs 8°F warmer. North of downtown, the OIT campus, on its hill since 1964, sits 200 feet above the floor, plans for −12°F and runs 8°F warmer at bloom. Wild Klamath plum grows in the sage steppe at Moore Park, at the south end of the lake.

Everything we sell rated −20°F or colder clears these spots with at least 7°F to spare, so pick by bloom. Downtown is the zero point on the spring layer, and with the airport's median last frost on June 11, zero isn't a great place for an apricot. Put early bloomers on Stewart Lenox, Fairhaven and the OIT hill: Tomcot and Sungold apricots, Redstar peach, Rainier cherry, Santa Rosa plum and SnowCzar almond. Chicago Hardy Fig, rated −10°F, is worth a try against a south wall downtown, on a geothermal lot or on Stewart Lenox.

Altamont, Moyina Heights and the south suburbs

Altamont spreads south and east of the city along South 6th Street and Crater Lake Parkway (OR 39). Its center plans for −13°F, zone 5b, on ground 40 feet above the floor, and runs 2°F warmer than downtown at bloom, but within 3 miles the floor runs −15°F. DEQ's smoke surveys found the worst winter air in what it calls the south suburban area and "the Valley" southeast of the city, the low ground where most of the homes are, with its Peterson School monitor reading highest. Smoke goes where the cold, still air goes.

Hager plans for −14°F and runs 1°F colder than downtown at bloom, and Pine Grove −16°F. Henley, 4 miles southeast on OR 39 and 10 feet above its floor, plans for −16°F and runs 3°F colder at bloom, and Midland, 8 miles south on US 97, −16°F and 2°F colder. The map gives the airport station's site −18°F.

Moyina Heights sits up the slope toward Hogback Mountain, 200 feet above the floor. It plans for −13°F and runs 5°F warmer than downtown at bloom, but the map types it as a draw, and draws carry cold down through bench ground: within 3 miles the warmest tenth of the ground runs −13°F and the coldest −16°F. Plant the shoulders, not the draw bottoms. The −20°F trees clear all of this, so put apples, haskap and bush fruit on the low ground in Henley, Midland and lower Altamont, and stone fruit and pears on the Moyina Heights shoulders and Miller Hill's slopes.

Keno, Worden, Dorris and the Klamath River

Keno sits on the Klamath River southwest of town along OR 66, where Keno Dam holds the reach below Lake Ewauna at a nearly constant level. It plans for −21°F, MFTC zone 4b, with a typical winter of −1°F, on a river bottom 20 feet above the floor, and runs 2°F colder than downtown at bloom. The Keno station only goes back to 2009; its 30-year number works out to −23°F, colder than anything it has read, and its coldest so far is −20°F on January 6, 2017.

Worden, 14 miles south on US 97 near the California line, plans for −20°F on a river bottom and runs 3°F colder than downtown at bloom. On the flats around it, a few low knolls still carry island names. Horsehead Island, 70 feet above the floor, plans for −19°F and runs 6°F warmer than downtown at bloom, and Zuckerman Island, 80 feet up, plans for −18°F and runs 7°F warmer, a 9°F to 10°F swing over Worden's river bottom.

Dorris, in California's Butte Valley, sits higher at 4,249 feet. It plans for −18°F, zone 5a, 90 feet above its own floor, and runs 1°F colder than downtown at bloom; within 3 miles the floor runs −19°F and the benches −16°F. The −25°F list fits all of this section, PF-24C Cold Hardy peach, Red Gold nectarine and Stella cherry among them. Bing and Santa Rosa (−20°F) clear Dorris and the knolls and are worth a try by a south wall in Keno or Worden. Keep stone fruit and pears on the knolls.

Merrill, Malin, Tulelake and the old lake beds

South of the Klamath Hills the floor flattens into the drained beds of Lower Klamath and Tule lakes, which the Klamath Project turned into farmland starting in 1912. Merrill, on the Lost River just north of them, plans for −20°F, MFTC zone 4b, with a typical winter of −3°F, right at floor level, and runs 2°F colder than downtown at bloom. The old Merrill station bottomed out at −23°F in the January 1962 cold snap.

Malin sits on the old bottom of Tule Lake at 4,066 feet. Bohemian (Czech) families settled it in 1909, and it's known for horseradish; our Horseradish has come through −50°F. Malin plans for −20°F, zone 5a, and runs 2°F colder than downtown at bloom, and even the warmest tenth of the ground within 3 miles runs −19°F. Turkey Hill, the old island just north of town, plans for −15°F on its flank and reads 15°F warmer at bloom, but it's steep, about a 51 percent grade.

Tulelake, California, at 4,038 feet on the old Tule Lake bed, is the lowest town we checked. It plans for −22°F, zone 4b, with a typical winter of −4°F, and reads 1°F colder than downtown at bloom. There's no bench ground within 3 miles. Its station has 76 years on file, a coldest reading of −28°F on January 22, 1962, and runs a median 3°F colder than the Lower Klamath station, 12 miles away and 60 feet higher.

So winter here runs 7°F to 9°F colder than downtown, and bloom-night frost is as flat as the ground. The −25°F list fits. Stone fruit on open lake bed is a gamble; give the floor to apples, haskap and bush fruit.

Olene, Bonanza, Yonna and Sprague River

The Lost River runs past Bonanza and through Olene Gap, a narrow spot on the river near Olene, on its way to Merrill and Tule Lake. Olene, about 10 miles southeast of town on OR 140, sits on a toe slope 50 feet above the floor, plans for −16°F, zone 5a, and runs 2°F warmer than downtown at bloom, good enough for the hardier stone fruit. Bonanza, on the Lost River with Bonanza Big Springs near downtown, plans for −21°F, zone 4b, with a typical winter of −4°F, and runs 1°F colder at bloom; its early farms grew fruits and vegetables. To the north, Yonna plans for −20°F and runs 3°F colder at bloom. The old Yonna station recorded −30°F on January 15, 1917, and ran a median 9°F colder than the old Klamath Falls station over 29 years.

Sprague River, up its valley in the northeast corner, plans for −27°F, zone 4a, with a typical winter of −9°F. The old Sprague River station, a bit higher at 4,483 feet, has the coldest reading on file at any station in or around this map, −32°F on December 9, 1972, and ran a median 11°F colder than the old Klamath Falls station. Its spring reading is 2°F warmer than downtown, so winter is what sorts things out there. The −25°F list fits Olene, Bonanza and Yonna; Sprague River wants the −30°F list at least.

Algoma, Shady Pine and Modoc Point on the east shore

North of town, US 97 follows the east shore of Upper Klamath Lake below Plum Hills, Bald Hill and Naylox Mountain. Much of the shore was marsh, and a lot was drained, including 1,200 acres at Algoma in 1914. Algoma plans for −16°F and Shady Pine −15°F, and they run 5°F colder than downtown on a still bloom night. That's drained marsh at the foot of steep hills: cold slides off the slopes after dark and settles on the flat, grassy shore. Modoc Point plans for −18°F and runs 2°F colder at bloom.

Up the slope it changes fast. The bench at Bald Hill, 750 feet above the floor, plans for −11°F and runs 13°F warmer than downtown at bloom. Every −20°F tree clears this shore, so put apples, haskap and currants on the flats and climb for anything that blooms early. Past Modoc Point the map ends; our nearest other map is Bend, Redmond and Sisters in Central Oregon.

Spring frost and bloom in the Klamath Basin

NOAA station records for 1991 to 2020 give these median frost dates:

• Klamath Falls airport station (4,083 ft, on the floor at Kingsley Field): last 32°F June 11, last 28°F May 21, first fall 32°F September 17, 98 frost-free days; one year in ten the last 32°F comes June 25 or later.
• Klamath Falls Ag station (4,092 ft, also on the floor): June 11 and May 22, 98 days.
• Tulelake (4,038 ft, on the old lake bed): June 9 and May 20, 99 days.
• Lower Klamath (4,098 ft, California side): June 11 and May 13, but first fall frost September 4, for 90 days.

No station in town has frost dates. The airport and Ag station are the nearest, both on the floor below town and both a median 3°F colder than the old Klamath Falls station in winter. Benches that read 5°F to 8°F warmer than downtown at bloom should see their last frost well before the floor does, but no station up there has dates. These stations all fall well under the 135 frost-free days the University of Vermont uses to mark short-season country, so late apples, pears and grapes may not ripen in the shortest-season spots.

Open blossoms of nearly every tree fruit start dying near 28°F (Michigan State's numbers). With the airport's median last 28°F on May 21, a tree in full bloom there before May 21 sees a 28°F night after its flowers open in at least half of springs. OSU Extension says June nights in the high 30s°F to low 40s°F are common in Klamath Falls and frost is possible almost any time.

Height saves the crop. On spring frost nights the cold layer in an orchard usually tops out 30 to 200 feet above the ground (the FAO's frost protection manual), and the benches around town, 130 to 200 feet up, read 5°F to 8°F warmer than downtown at bloom. NC State's fruit people say 3°F to 4°F can separate no crop from a full one. Put stone fruit and pears on ground that reads warmer than downtown, and give the colder floor to apples (only about 15 percent of blossoms need to set for a crop), haskap (open flowers take 19°F) and bush fruit. Unless the fruit grows in clusters like cherries and grapes, most fruit can lose half its blossoms with little effect; frost just thins it.

Bob Purvis's rule fits here: an east slope warms quickly on a frosty morning, and a north slope holds early bloomers back. OSU's Central Oregon fruit guide adds: skip west and south exposures, which push bloom earlier. Don't plant the dead end of a hollow, clear brush at the bottom of a slope so the cold keeps moving, and through bloom mow under 2 inches and water a day or two before a frost night. Frost cloth of 0.5, 0.9 and 1.5 ounces per square yard gains about 4°F, 6°F and 8°F, by Alabama Extension's numbers.

What the weather records say

The old winters went deeper. The coldest readings on file in NOAA station records: −32°F at the old Sprague River station (December 9, 1972), −30°F at the old Yonna station (January 15, 1917), −28°F at Tulelake (January 22, 1962), −25°F at the Klamath Falls airport and Ag stations (January 23, 1962), and −17°F at the old Klamath Falls station (December 9, 1972).

Since the 1995 to 1996 winter, which our planning lows are built on, the hardest cold snaps came in December 2013 (Lower Klamath −22°F, the airport and Ag stations −20°F), January 2017 (Tulelake −23°F, Lower Klamath and Keno −20°F, the airport and Ag stations −19°F) and February 2025 (Tulelake −21°F, the airport and Ag stations −14°F).

OSU Extension puts Klamath Falls in USDA zone 6b (−5°F to 0°F), and NOAA station records give the airport an average yearly low of −3°F. USDA's map is built on that kind of average night. Across NOAA's stations, the worst night in about 30 winters runs a median 13°F below a station's average winter low, which is why our zones read a zone or more colder than USDA's.

What you can grow here

Everything we sell rated −30°F or colder, most of the list, clears every named place on this map, and everything rated −25°F clears all but the Sprague River valley. So pick by bloom and by site.

Klamath Falls, its benches and the south suburbs: −11°F to −16°F

Everything rated −20°F or colder fits: Bing and Lapins sweet cherries, Mericrest nectarine, Glohaven and Blushingstar peaches (Blushingstar came through −25°F at our place on January 13, 2024 without damage), Harlayne apricot, St. Edmund's Pippin apple, Seckel pear and Montana Trial Persimmon. Worth a try: Chicago Hardy Fig (−10°F) by a south wall on lots that plan for −11°F to −13°F.

The Klamath River, the Lost River and the old lake beds: −18°F to −22°F

Everything rated −25°F or colder fits: PF-24C and Contender peaches, Hardired nectarine, Stella and Rainier sweet cherries, Superior plum (Toka is a good pollenizer for Superior; see our pollination maps), Goldrich apricot, Honeysweet pear on a knoll, and Honeycrisp, Liberty and Northern Spy apples. Worth a try: Bing and Santa Rosa (−20°F) by a south wall in Merrill, Keno, Worden or Tulelake; they clear Dorris, Modoc Point, Malin and the knolls near Worden outright.

The Sprague River valley: around −27°F

Everything rated −30°F or colder fits, and −35°F or colder gives you room: Black Gold sweet cherry, Evans Bali tart cherry, Westcot apricot, Brookred plum, Summercrisp pear, Haralson apple, and Kerr and Trailman applecrabs (if you only plant one tree, make it one of these). Worth a try: −25°F trees like PF-24C and SnowCzar on your highest ground.

Bush fruit, roots, soil and water

Honeyberries, Montana Black Currant and Red Lake currant clear every spot here; both currants fruited well for us after flower buds saw about 22°F. Roots are the weak link, and snow over them is the best protection; Bud 118 apple rootstock has seen near −50°F with no damage under snow at Ed Schultz's farm in Gallatin Gateway, Montana. The southeast floor gets the least snow, so mulch there and don't let the soil go into winter bone dry. Drip is the only irrigation we advise in dry country. On zone 4 ground (Keno, Worden, Merrill, Tulelake, Bonanza, Sprague River) taper water from mid-August so trees harden off. The floor is old lake bed, with drained marsh in places, so test drainage: dig 2 feet, fill it, let it drain, refill it, and under 10 hours is well drained. We haven't found a local source on fire blight, codling moth or voles here, so ask OSU Extension in Klamath County.

Questions people ask

What growing zone is Klamath Falls?

Downtown Klamath Falls plans for −13°F, MFTC zone 5b, and the floor south of town −16°F to −18°F. OSU Extension puts it in USDA zone 6b; USDA's zones are built on an average winter's coldest night, ours on the bad night we plan for.

When is the last frost in Klamath Falls?

At the Klamath Falls airport station, on the floor 6 miles south of downtown, the 1991 to 2020 median last 32°F frost is June 11 and the last 28°F May 21, with 98 frost-free days. No station downtown has frost dates, and the benches above town run 6°F to 8°F warmer than downtown on a still spring night.

Can you grow peaches in Klamath Falls?

For winter, yes: downtown plans for −13°F and every peach we sell has come through −25°F or colder. The crop is the risk, since peach blossoms start taking damage around 26°F at first bloom and the airport's median last 28°F is May 21. Plant them on Stewart Lenox, Fairhaven or the OIT hill.

Does Upper Klamath Lake freeze?

Often, but not every winter. ODFW's fishing reports had it frozen except near the outlet and a few springs along US 97 in January 2022, but mostly ice-free at the end of January 2024. With a mean depth of 14 feet it freezes early and gives the shore little warmth in midwinter.

Why is Tulelake so cold?

It's the lowest town we checked, at 4,038 feet on the bed of Tule Lake, a basin with no natural outlet, and cold air pools there on clear, still nights. Tulelake plans for −22°F, MFTC zone 4b, and its coldest reading on file is −28°F, on January 22, 1962.

Warmer spots, colder spots

Here's the number to plan for at named places on the map, warmest first. Each one is the 1-in-30-year low for that spot: the cold hardiness calculator's number from the same weather stations, sharpened by our microclimate model for the ground right there. Zone is our MFTC zone, set by that one bad night, not by an average.

The weather stations behind it

These are the long-record stations in and around this map, with each one's own numbers since the winter of 1995-96. The last column is this map's 30-year number right at the station, which won't match the station exactly: it's a blend of the stations around it, the way the calculator works everywhere.

Source: NOAA records through ACIS, winters 1995-96 through 2025-26. What the "carried forward," "gaps filled" and AWOS rows mean is explained in how our microclimate maps work.