Frost dates for 97857Lostine, OR
The average last spring frost in Lostine is June 7 and the average first fall frost is September 9, giving a typical growing season of about 91 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Jun 7
- Average first fall frost
- Sep 9
- Growing season
- 91 days
Safer after Jul 7 (1-in-10 risk)
Possible by Aug 24 (1-in-10 risk)
Last frost typically in 217 days
Frost risk by date
NOAA reports frost dates as probabilities. The middle date is the average (a 50% chance). For spring, the 10% date is a safer planting date: frost after it happens in about 1 year in 10. Light frost (36°F) can damage tender plants; a hard freeze (28°F) kills most annuals.
| Temperature | Last spring: 90% / 50% / 10% chance | First fall: 10% / 50% / 90% chance | Growing season (50%) | Years with at least one |
|---|---|---|---|---|
| Light frost (36°F) | — | — | 53 days | 100% |
| Frost / freeze (32°F) | May 14 · Jun 7 · Jul 7 | Aug 24 · Sep 9 · Sep 27 | 91 days | 100% |
| Hard freeze (28°F) | Apr 29 · May 11 · May 29 | Sep 5 · Sep 24 · Oct 8 | 133 days | 100% |
Planting calendar for Lostine
Planting windows from the University of Maryland Extension calendar, shifted to your average frost dates. Use them as a starting point and adjust for seed packet instructions and local conditions.
| Crop | Task | Window |
|---|---|---|
| Tomatoes | Start seeds indoors | May 7 – Jul 13 |
| Tomatoes | Transplant outdoors | Jun 23 – May 20 |
| Peppers | Start seeds indoors | May 7 – Jun 7 |
| Peppers | Transplant outdoors | Jul 7 – Aug 7 |
| Eggplant | Start seeds indoors | May 24 – Jun 22 |
| Eggplant | Transplant outdoors | Jul 7 – Aug 7 |
| Cucumbers | Sow outdoors | Jul 7 – May 30 |
| Summer squash | Sow outdoors | Jun 23 – Aug 7 |
| Winter squash & pumpkins | Sow outdoors | Jul 7 – Aug 7 |
| Snap beans | Sow outdoors | Jun 23 – Jun 22 |
| Sweet corn | Sow outdoors | Jun 23 – May 20 |
| Watermelon & cantaloupe | Sow outdoors | Jul 7 – Aug 7 |
| Okra | Sow outdoors | Jun 30 – Jul 23 |
| Peas | Sow outdoors (spring) | May 7 – Jun 22 |
| Potatoes | Plant outdoors (spring) | May 7 – Jul 7 |
| Onions | Start seeds indoors (spring) | Mar 26 – Apr 22 |
| Onions | Transplant outdoors (spring) | May 24 – Jun 22 |
| Broccoli | Start seeds indoors (spring) | Apr 19 – May 23 |
| Broccoli | Transplant outdoors (spring) | May 24 – Jun 22 |
| Broccoli | Start seeds indoors (fall) | May 10 – May 20 |
| Broccoli | Transplant outdoors (fall) | Jun 9 – Jun 20 |
| Cabbage | Start seeds indoors (spring) | Apr 9 – May 7 |
| Cabbage | Transplant outdoors (spring) | May 7 – Jun 7 |
| Cabbage | Start seeds indoors (fall) | Apr 30 – May 30 |
| Cabbage | Transplant outdoors (fall) | May 30 – Jun 30 |
| Leaf lettuce | Sow outdoors (spring) | May 7 – Jul 23 |
| Leaf lettuce | Sow outdoors (fall) | May 30 – Jul 16 |
| Spinach | Sow outdoors (spring) | Apr 30 – Jun 13 |
| Spinach | Sow outdoors (fall) | Jun 16 – Jul 21 |
| Radishes | Sow outdoors (spring) | May 7 – Jun 27 |
| Radishes | Sow outdoors (fall) | May 30 – Jul 31 |
| Kale | Sow outdoors (spring) | May 24 – Jun 13 |
| Kale | Sow outdoors (fall) | May 23 – Jun 30 |
| Carrots | Sow outdoors (spring) | Jun 7 – Jul 23 |
| Carrots | Sow outdoors (fall) | Apr 30 – Jun 15 |
| Garlic | Plant outdoors (fall) | Aug 30 – Sep 30 |
Where these dates come from
ZIP code 97857 is matched to the NOAA station Wallowa, OR, 11.5 km away, at 2,923 ft elevation (378 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Wallowa, OR (used) | 2,923 ft | Jun 7 | Sep 9 |
| Joseph, OR | 4,184 ft | May 24 | Oct 1 |
| Enterprise 20 Nne, OR | 3,280 ft | Jun 8 | Sep 5 |
| Elgin, OR | 2,697 ft | May 24 | Sep 18 |
Frost dates near Lostine
- Wallowa, OR 97885 · last Jun 7, first Sep 9
- Enterprise, OR 97828 · last May 24, first Oct 1
- Joseph, OR 97846 · last May 24, first Oct 1
- Cove, OR 97824 · last May 11, first Sep 26
- Elgin, OR 97827 · last May 24, first Sep 18
- Imbler, OR 97841 · last May 6, first Oct 1
- Union, OR 97883 · last May 11, first Sep 26
- Summerville, OR 97876 · last May 6, first Oct 1
Frequently asked questions
- When is the last frost in Lostine, OR?
- For ZIP code 97857, the average last spring frost (32°F) is June 7, based on NOAA 1991-2020 climate normals for the Wallowa, OR weather station. There is a 1-in-10 chance of a frost after July 7.
- When is the first frost in Lostine, OR?
- The average first fall frost (32°F) is September 9. There is a 1-in-10 chance of frost by August 24, so tender plants are at risk from that point on.
- How long is the growing season in 97857?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 91 days long.
- Are these frost dates a forecast?
- No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.