Klamath Falls, OR planting zone & frost dates

Klamath Falls is in USDA hardiness zone 6b. The last spring frost usually comes around June 9 and the first fall frost around September 18, for a growing season of about 99 days.

USDA hardiness zone6bavg. extreme winter low -5°F to 0°F
Average last spring frostJune 990% chance of no frost after June 26
Average first fall frostSeptember 1810% chance of frost by September 4
Growing season99 daysfrost-free days in an average year

Planting calendar for Klamath Falls

Dates are counted from the average last spring frost (June 9) using the typical timing recommended by U.S. extension services. Warm-season crops go out only after the danger of frost has passed and the soil has warmed.

CropWhen
TomatoesStart seeds indoors: Apr 14 – Apr 28
Transplant outdoors: Jun 16 – Jun 23
PeppersStart seeds indoors: Mar 31 – Apr 14
Transplant outdoors: Jun 23 – Jun 30
EggplantStart seeds indoors: Mar 31 – Apr 14
Transplant outdoors: Jun 23 – Jun 30
BroccoliStart seeds indoors: Mar 31 – Apr 14
Transplant outdoors: May 12 – May 26
CabbageStart seeds indoors: Mar 31 – Apr 14
Transplant outdoors: May 12 – May 26
Onions (sets)Plant outdoors: May 12 – May 26
PeasSow outdoors: Apr 28 – May 12
SpinachSow outdoors: Apr 28 – May 12
LettuceSow outdoors: May 12 – May 26
CarrotsSow outdoors: May 12 – May 26
PotatoesPlant outdoors: May 12 – May 26
BeansSow outdoors: Jun 16 – Jun 23
Sweet cornSow outdoors: Jun 16 – Jun 23
CucumbersSow outdoors: Jun 16 – Jun 23
Squash & zucchiniSow outdoors: Jun 16 – Jun 23
BasilStart seeds indoors: Apr 28 – May 12
Transplant outdoors: Jun 16 – Jun 23

Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Jul 24 (8 weeks before the average first fall frost on Sep 18).

Useful for zone 6b gardens

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Frost risk in detail

90% chance50% chance10% chance
Last 32°F frost in spring is afterMay 22Jun 9Jun 26
First 32°F frost in fall is beforeOct 1Sep 18Sep 4

How to read it: in spring there is a 10% chance of a frost after June 26, so that is a safe date for tender plants. In fall there is a 10% chance of frost before September 4. A hard freeze (28°F) usually ends around May 21.

Hardiness zone by ZIP code in Klamath Falls

Nearby cities

All cities in Oregon → · Other zone 6b cities →

Questions

What growing zone is Klamath Falls, OR?

Klamath Falls is in USDA Plant Hardiness Zone 6b (average extreme winter low -5°F to 0°F), according to the USDA 2023 map. Some ZIP codes of the city fall in zone 7a.

When is the last frost in Klamath Falls?

The average last spring frost (32°F) in Klamath Falls is June 9. There is still a 10% chance of frost until June 26.

When can I plant tomatoes in Klamath Falls?

Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Jun 16 – Jun 23. Start seeds indoors 6–8 weeks before the last frost.

Frost dates: NOAA U.S. Climate Normals 1991–2020, station Klamath Falls Intl Ap, OR (USW00094236), 9.9 km (6.1 mi) from the city center, elevation 1245 m, based on 21 years of records. Hardiness zone: USDA Plant Hardiness Zone Map 2023 for the ZIP code nearest to the city center. Microclimates (valleys, hills, cities, coasts) can be warmer or colder: check the local forecast before planting. How we calculate the data.