Klamath Falls, OR Frost Dates
Average frost dates, USDA hardiness zone, and growing season length for Klamath Falls, Oregon.
Gardening in Klamath Falls
Southern Oregon's high-desert lake city sits at 4,100 feet — a completely different climate from the Willamette Valley.
Zone 6a with only 126 frost-free days. The Klamath Basin's high-altitude cold, intense sun, and geothermal warmth create unique conditions. Summer days are hot; nights are cold.
Klamath Falls' geothermal resources have been used for greenhouse heating since the early 1900s — extended-season growing is literally built into the city's infrastructure.
What This Means for Klamath Falls Gardeners
The average last spring frost in Klamath Falls is around May 15, and the average first fall frost arrives around September 18. That gives you approximately 126 frost-free days to work with.
126 frost-free days means every warm day counts. Focus on cold-hardy crops that thrive in your moderate temperatures: kale, lettuce, peas, radishes, potatoes, and root vegetables. For warm-season crops, choose only the shortest-season varieties (sub-65-day tomatoes, 55-day beans) and start everything indoors. Season extension — row covers, cold frames, plastic mulch — isn't a luxury here, it's essential infrastructure.
These dates are based on NOAA 30-year Climate Normal data for the Klamath Falls area. Your actual frost dates could shift 2-3 weeks in either direction in any given year. Learn more about our data sources.
What to Grow in Klamath Falls
With 126 frost-free days, Klamath Falls gardeners need to plan strategically — start warm-season crops indoors and choose short-season varieties. Cool-season crops are your strength, thriving in the moderate temperatures that define your growing window. Recommended starting points: kale, lettuce, peas, carrots, potatoes, radishes, garlic, and short-season tomatoes.
See the full Oregon planting guide for all 40 plants: Oregon Planting Calendar. Or enter your zip code for exact planting dates personalized to Klamath Falls.
More About Zone 6A
Klamath Falls is in USDA Hardiness Zone 6A, which means average annual extreme minimum temperatures between -10°F to -5°F. View the full Zone 6A planting guide.
See the complete planting calendar for Oregon: Oregon Planting Calendar.
Other Cities in Oregon
Frequently Asked Questions
These dates are based on NOAA's 30-year Climate Normal data for the Klamath Falls area. They represent historical averages, not predictions. In any given year, the actual last frost could be 2-3 weeks earlier or later. Microclimates within Klamath Falls (urban heat islands, hilltops, low-lying valleys) can also shift your local frost dates by a week or more.
Start everything possible indoors — your 126-day season doesn't leave room for a slow start. Direct sow only the fastest, hardiest crops (radishes, lettuce, peas) 3-4 weeks before last frost (May 15). Choose short-season varieties for warm crops. Enter your zip code for exact dates.