Frost dates for 97448Junction City, OR
The average last spring frost in Junction City is April 11 and the average first fall frost is October 23, giving a typical growing season of about 196 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 11
- Average first fall frost
- Oct 23
- Growing season
- 196 days
Safer after May 9 (1-in-10 risk)
Possible by Oct 6 (1-in-10 risk)
Last frost typically in 161 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) | Apr 24 · May 15 · Jun 8 | Sep 18 · Oct 7 · Oct 24 | 144 days | 100% |
| Frost / freeze (32°F) | Mar 15 · Apr 11 · May 9 | Oct 6 · Oct 23 · Nov 13 | 196 days | 100% |
| Hard freeze (28°F) | Feb 2 · Mar 3 · Mar 30 | Oct 20 · Nov 11 · Dec 12 | 252 days | 100% |
Planting calendar for Junction City
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 | Mar 11 – May 17 |
| Tomatoes | Transplant outdoors | Apr 27 – Jul 3 |
| Peppers | Start seeds indoors | Mar 11 – Apr 11 |
| Peppers | Transplant outdoors | May 11 – Jun 11 |
| Eggplant | Start seeds indoors | Mar 28 – Apr 26 |
| Eggplant | Transplant outdoors | May 11 – Jun 11 |
| Cucumbers | Sow outdoors | May 11 – Jul 13 |
| Summer squash | Sow outdoors | Apr 27 – Jun 11 |
| Winter squash & pumpkins | Sow outdoors | May 11 – Jun 11 |
| Snap beans | Sow outdoors | Apr 27 – Aug 5 |
| Sweet corn | Sow outdoors | Apr 27 – Jul 3 |
| Watermelon & cantaloupe | Sow outdoors | May 11 – Jun 11 |
| Okra | Sow outdoors | May 4 – May 27 |
| Peas | Sow outdoors (spring) | Mar 11 – Apr 26 |
| Potatoes | Plant outdoors (spring) | Mar 11 – May 11 |
| Onions | Start seeds indoors (spring) | Jan 28 – Feb 24 |
| Onions | Transplant outdoors (spring) | Mar 28 – Apr 26 |
| Broccoli | Start seeds indoors (spring) | Feb 21 – Mar 27 |
| Broccoli | Transplant outdoors (spring) | Mar 28 – Apr 26 |
| Broccoli | Start seeds indoors (fall) | Jun 23 – Jul 3 |
| Broccoli | Transplant outdoors (fall) | Jul 23 – Aug 3 |
| Cabbage | Start seeds indoors (spring) | Feb 11 – Mar 11 |
| Cabbage | Transplant outdoors (spring) | Mar 11 – Apr 11 |
| Cabbage | Start seeds indoors (fall) | Jun 13 – Jul 13 |
| Cabbage | Transplant outdoors (fall) | Jul 13 – Aug 13 |
| Leaf lettuce | Sow outdoors (spring) | Mar 11 – May 27 |
| Leaf lettuce | Sow outdoors (fall) | Jul 13 – Aug 29 |
| Spinach | Sow outdoors (spring) | Mar 4 – Apr 17 |
| Spinach | Sow outdoors (fall) | Jul 30 – Sep 3 |
| Radishes | Sow outdoors (spring) | Mar 11 – May 1 |
| Radishes | Sow outdoors (fall) | Jul 13 – Sep 13 |
| Kale | Sow outdoors (spring) | Mar 28 – Apr 17 |
| Kale | Sow outdoors (fall) | Jul 6 – Aug 13 |
| Carrots | Sow outdoors (spring) | Apr 11 – May 27 |
| Carrots | Sow outdoors (fall) | Jun 13 – Jul 29 |
| Garlic | Plant outdoors (fall) | Oct 13 – Nov 13 |
Where these dates come from
ZIP code 97448 is matched to the NOAA station Eugene Mahlon Sweet Ap, OR, 7.9 km away, at 353 ft elevation (22 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Eugene Mahlon Sweet Ap, OR (used) | 353 ft | Apr 11 | Oct 23 |
| Fern Ridge-Veneta, OR | 485 ft | Apr 18 | Oct 25 |
| Corvallis 10 Ssw, OR | 312 ft | Apr 11 | Oct 30 |
| Corvallis Water Bureau, OR | 592 ft | May 15 | Oct 8 |
Frost dates near Junction City
- Alvadore, OR 97409 · last Apr 11, first Oct 23
- Harrisburg, OR 97446 · last Apr 11, first Oct 23
- Cheshire, OR 97419 · last Apr 18, first Oct 25
- Eugene, OR 97404 · last Apr 11, first Oct 23
- Monroe, OR 97456 · last Apr 11, first Oct 23
- Elmira, OR 97437 · last Apr 18, first Oct 25
- Veneta, OR 97487 · last Apr 18, first Oct 25
- Noti, OR 97461 · last Apr 18, first Oct 25
Frequently asked questions
- When is the last frost in Junction City, OR?
- For ZIP code 97448, the average last spring frost (32°F) is April 11, based on NOAA 1991-2020 climate normals for the Eugene Mahlon Sweet Ap, OR weather station. There is a 1-in-10 chance of a frost after May 9.
- When is the first frost in Junction City, OR?
- The average first fall frost (32°F) is October 23. There is a 1-in-10 chance of frost by October 6, so tender plants are at risk from that point on.
- How long is the growing season in 97448?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 196 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.