Last spring frost
Jun 9
Frost Dates for Klamath Falls, OR
First fall frost
Sep 18
Growing season
99 days
Hardiness zone
6b
In an average year around Klamath Falls, OR, the last spring frost (32°F) is about Jun 9 and the first fall frost is about Sep 18, giving roughly a 99-day growing season. To be safe most years, wait until May 22 before setting out tender plants.
Last spring frost
Dates the last frost of spring typically ends. Plant tender crops after the risk has passed for your comfort level.
| Frost intensity | Early (10%) | Average (50%) | Late (90%) |
|---|---|---|---|
| Freeze (32°F) | Jun 26 | Jun 9 | May 22 |
| Hard (28°F) | Jun 12 | May 21 | May 2 |
| Severe (24°F) | May 20 | May 1 | Apr 13 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 32°F | Jun 26 | Jun 21 | Jun 16 | Jun 12 | Jun 9 | Jun 6 | Jun 3 | May 30 | May 22 |
| 28°F | Jun 12 | Jun 5 | Jun 1 | May 26 | May 21 | May 16 | May 13 | May 8 | May 2 |
| 24°F | May 20 | May 12 | May 7 | May 3 | May 1 | Apr 28 | Apr 24 | Apr 19 | Apr 13 |
| 20°F | May 1 | Apr 25 | Apr 20 | Apr 16 | Apr 12 | Apr 8 | Apr 4 | Mar 30 | Mar 21 |
| 16°F | Apr 11 | Apr 3 | Mar 27 | Mar 20 | Mar 14 | Mar 8 | Mar 2 | Feb 25 | Feb 15 |
First fall frost
Dates the first frost of fall typically arrives. Count back by a crop's days-to-maturity to know your planting cutoff.
| Frost intensity | Early (10%) | Average (50%) | Late (90%) |
|---|---|---|---|
| Freeze (32°F) | Sep 4 | Sep 18 | Oct 1 |
| Hard (28°F) | Sep 17 | Oct 2 | Oct 17 |
| Severe (24°F) | Oct 2 | Oct 17 | Nov 1 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 32°F | Sep 4 | Sep 9 | Sep 13 | Sep 16 | Sep 18 | Sep 20 | Sep 23 | Sep 27 | Oct 1 |
| 28°F | Sep 17 | Sep 23 | Sep 26 | Sep 29 | Oct 2 | Oct 5 | Oct 7 | Oct 12 | Oct 17 |
| 24°F | Oct 2 | Oct 6 | Oct 10 | Oct 14 | Oct 17 | Oct 20 | Oct 23 | Oct 26 | Nov 1 |
| 20°F | Oct 14 | Oct 20 | Oct 23 | Oct 26 | Oct 30 | Nov 2 | Nov 5 | Nov 10 | Nov 17 |
| 16°F | Oct 26 | Nov 1 | Nov 5 | Nov 10 | Nov 13 | Nov 18 | Nov 22 | Nov 28 | Dec 6 |
Growing season is measured at 32°F with about 50% probability. Hardiness zone from the 2023 USDA map; frost normals from NOAA 1991-2020.
Where this data comes from
@endif These dates are computed from the nearest official weather station with long-term records: Klamath Falls Intl Ap, Or, about 13.7 miles away@if(!empty($station['elevation_ft'])), at 4,084 ft elevation. The further the station and the greater the elevation difference from your yard, the more your local frost timing can vary.
How we calculate these dates
Frost and freeze dates come from the NOAA 1991–2020 U.S. Climate Normals, the National Oceanic and Atmospheric Administration's 30-year averages for each weather station. A date shown at the 50% level is the median: in half of years the frost falls on or before it. The 10% and 90% columns show the early and late ends of the range, so you can plant on the odds you're comfortable with. These are long-term averages, not a forecast for this year - always check your local outlook before planting.
Source: NOAA National Centers for Environmental Information, 1991–2020 Climate Normals (public domain). Harman is not affiliated with or endorsed by NOAA.
Frequently asked questions
When is the last frost in Klamath Falls, OR?
On average, the last spring frost (32°F) around Klamath Falls, OR is about Jun 9. In cooler years it can run later, so for a safer bet many gardeners wait until May 22.
When is the first frost in the fall?
The first fall frost around Klamath Falls, OR typically arrives about Sep 18. Count back by a crop's days to maturity to find the latest date you can plant it.
When can I plant tomatoes and other tender crops?
Tender crops like tomatoes, peppers and basil are damaged by frost, so wait until the last spring frost has passed - around Jun 9 on average, or May 22 to be safe most years.
How long is the growing season here?
The frost-free growing season (between the last spring and first fall 32°F frost) is about 99 days in a typical year.
Are these dates a forecast for this year?
No. They are 30-year averages from the NOAA 1991–2020 Climate Normals, not a prediction for the current year. Use them for planning and always check your local weather forecast before planting or protecting crops.
Local weather for 97625 Planting calendar → Oregon frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026