Frost dates for 97640Summer Lake, OR
The average last spring frost in Summer Lake is June 8 and the average first fall frost is September 15, giving a typical growing season of about 96 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Jun 8
- Average first fall frost
- Sep 15
- Growing season
- 96 days
Safer after Jun 25 (1-in-10 risk)
Possible by Aug 31 (1-in-10 risk)
Last frost typically in 218 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) | — | — | 67 days | 100% |
| Frost / freeze (32°F) | May 20 · Jun 8 · Jun 25 | Aug 31 · Sep 15 · Sep 28 | 96 days | 100% |
| Hard freeze (28°F) | Apr 30 · May 18 · Jun 10 | Sep 12 · Sep 29 · Oct 12 | 130 days | 100% |
Planting calendar for Summer Lake
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 8 – Jul 14 |
| Tomatoes | Transplant outdoors | Jun 24 – May 26 |
| Peppers | Start seeds indoors | May 8 – Jun 8 |
| Peppers | Transplant outdoors | Jul 8 – Aug 8 |
| Eggplant | Start seeds indoors | May 25 – Jun 23 |
| Eggplant | Transplant outdoors | Jul 8 – Aug 8 |
| Cucumbers | Sow outdoors | Jul 8 – Jun 5 |
| Summer squash | Sow outdoors | Jun 24 – Aug 8 |
| Winter squash & pumpkins | Sow outdoors | Jul 8 – Aug 8 |
| Snap beans | Sow outdoors | Jun 24 – Jun 28 |
| Sweet corn | Sow outdoors | Jun 24 – May 26 |
| Watermelon & cantaloupe | Sow outdoors | Jul 8 – Aug 8 |
| Okra | Sow outdoors | Jul 1 – Jul 24 |
| Peas | Sow outdoors (spring) | May 8 – Jun 23 |
| Potatoes | Plant outdoors (spring) | May 8 – Jul 8 |
| Onions | Start seeds indoors (spring) | Mar 27 – Apr 23 |
| Onions | Transplant outdoors (spring) | May 25 – Jun 23 |
| Broccoli | Start seeds indoors (spring) | Apr 20 – May 24 |
| Broccoli | Transplant outdoors (spring) | May 25 – Jun 23 |
| Broccoli | Start seeds indoors (fall) | May 16 – May 26 |
| Broccoli | Transplant outdoors (fall) | Jun 15 – Jun 26 |
| Cabbage | Start seeds indoors (spring) | Apr 10 – May 8 |
| Cabbage | Transplant outdoors (spring) | May 8 – Jun 8 |
| Cabbage | Start seeds indoors (fall) | May 6 – Jun 5 |
| Cabbage | Transplant outdoors (fall) | Jun 5 – Jul 6 |
| Leaf lettuce | Sow outdoors (spring) | May 8 – Jul 24 |
| Leaf lettuce | Sow outdoors (fall) | Jun 5 – Jul 22 |
| Spinach | Sow outdoors (spring) | May 1 – Jun 14 |
| Spinach | Sow outdoors (fall) | Jun 22 – Jul 27 |
| Radishes | Sow outdoors (spring) | May 8 – Jun 28 |
| Radishes | Sow outdoors (fall) | Jun 5 – Aug 6 |
| Kale | Sow outdoors (spring) | May 25 – Jun 14 |
| Kale | Sow outdoors (fall) | May 29 – Jul 6 |
| Carrots | Sow outdoors (spring) | Jun 8 – Jul 24 |
| Carrots | Sow outdoors (fall) | May 6 – Jun 21 |
| Garlic | Plant outdoors (fall) | Sep 5 – Oct 6 |
Where these dates come from
ZIP code 97640 is matched to the NOAA station Summer Lake 1 S, OR, 1.7 km away, at 4,192 ft elevation (2 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Summer Lake 1 S, OR (used) | 4,192 ft | Jun 8 | Sep 15 |
| Silver Lake Rs, OR | 4,385 ft | — | — |
| Paisley, OR | 4,360 ft | Jun 6 | Sep 14 |
| The Poplars, OR | 4,310 ft | — | — |
Frost dates near Summer Lake
- Silver Lake, OR 97638 · last —, first —
- Paisley, OR 97636 · last Jun 6, first Sep 14
- Christmas Valley, OR 97641 · last —, first —
- Fort Rock, OR 97735 · last —, first —
- Bly, OR 97622 · last May 31, first Sep 21
- Beatty, OR 97621 · last May 31, first Sep 21
- Sprague River, OR 97639 · last Jun 9, first Sep 18
- Chemult, OR 97731 · last —, first —
Frequently asked questions
- When is the last frost in Summer Lake, OR?
- For ZIP code 97640, the average last spring frost (32°F) is June 8, based on NOAA 1991-2020 climate normals for the Summer Lake 1 S, OR weather station. There is a 1-in-10 chance of a frost after June 25.
- When is the first frost in Summer Lake, OR?
- The average first fall frost (32°F) is September 15. There is a 1-in-10 chance of frost by August 31, so tender plants are at risk from that point on.
- How long is the growing season in 97640?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 96 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.