Frost dates for 97840Oxbow, OR
The average last spring frost in Oxbow is April 2 and the average first fall frost is November 5, giving a typical growing season of about 216 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 2
- Average first fall frost
- Nov 5
- Growing season
- 216 days
Safer after Apr 20 (1-in-10 risk)
Possible by Oct 24 (1-in-10 risk)
First frost typically in 3 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 6 · Apr 21 · May 7 | Oct 13 · Oct 26 · Nov 8 | 185 days | 100% |
| Frost / freeze (32°F) | Mar 15 · Apr 2 · Apr 20 | Oct 24 · Nov 5 · Nov 19 | 216 days | 100% |
| Hard freeze (28°F) | Feb 26 · Mar 13 · Apr 1 | Nov 1 · Nov 16 · Nov 30 | 246 days | 100% |
Planting calendar for Oxbow
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 2 – May 8 |
| Tomatoes | Transplant outdoors | Apr 18 – Jul 16 |
| Peppers | Start seeds indoors | Mar 2 – Apr 2 |
| Peppers | Transplant outdoors | May 2 – Jun 2 |
| Eggplant | Start seeds indoors | Mar 19 – Apr 17 |
| Eggplant | Transplant outdoors | May 2 – Jun 2 |
| Cucumbers | Sow outdoors | May 2 – Jul 26 |
| Summer squash | Sow outdoors | Apr 18 – Jun 2 |
| Winter squash & pumpkins | Sow outdoors | May 2 – Jun 2 |
| Snap beans | Sow outdoors | Apr 18 – Aug 18 |
| Sweet corn | Sow outdoors | Apr 18 – Jul 16 |
| Watermelon & cantaloupe | Sow outdoors | May 2 – Jun 2 |
| Okra | Sow outdoors | Apr 25 – May 18 |
| Peas | Sow outdoors (spring) | Mar 2 – Apr 17 |
| Potatoes | Plant outdoors (spring) | Mar 2 – May 2 |
| Onions | Start seeds indoors (spring) | Jan 19 – Feb 15 |
| Onions | Transplant outdoors (spring) | Mar 19 – Apr 17 |
| Broccoli | Start seeds indoors (spring) | Feb 12 – Mar 18 |
| Broccoli | Transplant outdoors (spring) | Mar 19 – Apr 17 |
| Broccoli | Start seeds indoors (fall) | Jul 6 – Jul 16 |
| Broccoli | Transplant outdoors (fall) | Aug 5 – Aug 16 |
| Cabbage | Start seeds indoors (spring) | Feb 2 – Mar 2 |
| Cabbage | Transplant outdoors (spring) | Mar 2 – Apr 2 |
| Cabbage | Start seeds indoors (fall) | Jun 26 – Jul 26 |
| Cabbage | Transplant outdoors (fall) | Jul 26 – Aug 26 |
| Leaf lettuce | Sow outdoors (spring) | Mar 2 – May 18 |
| Leaf lettuce | Sow outdoors (fall) | Jul 26 – Sep 11 |
| Spinach | Sow outdoors (spring) | Feb 23 – Apr 8 |
| Spinach | Sow outdoors (fall) | Aug 12 – Sep 16 |
| Radishes | Sow outdoors (spring) | Mar 2 – Apr 22 |
| Radishes | Sow outdoors (fall) | Jul 26 – Sep 26 |
| Kale | Sow outdoors (spring) | Mar 19 – Apr 8 |
| Kale | Sow outdoors (fall) | Jul 19 – Aug 26 |
| Carrots | Sow outdoors (spring) | Apr 2 – May 18 |
| Carrots | Sow outdoors (fall) | Jun 26 – Aug 11 |
| Garlic | Plant outdoors (fall) | Oct 26 – Nov 26 |
Where these dates come from
ZIP code 97840 is matched to the NOAA station Brownlee Dam, ID, 15.6 km away, at 1,844 ft elevation (147 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Brownlee Dam, ID (used) | 1,844 ft | Apr 2 | Nov 5 |
| Halfway, OR | 2,653 ft | May 15 | Sep 24 |
| Richland, OR | 2,215 ft | May 10 | Oct 1 |
| Council, ID | 2,943 ft | May 10 | Oct 2 |
Frost dates near Oxbow
- Halfway, OR 97834 · last May 15, first Sep 24
- Richland, OR 97870 · last May 15, first Sep 24
- Council, ID 83612 · last May 10, first Oct 2
- Cambridge, ID 83610 · last May 15, first Sep 27
- New Meadows, ID 83654 · last —, first —
- Joseph, OR 97846 · last May 24, first Oct 1
- Mesa, ID 83643 · last May 10, first Oct 2
- Pollock, ID 83547 · last May 6, first Oct 9
Frequently asked questions
- When is the last frost in Oxbow, OR?
- For ZIP code 97840, the average last spring frost (32°F) is April 2, based on NOAA 1991-2020 climate normals for the Brownlee Dam, ID weather station. There is a 1-in-10 chance of a frost after April 20.
- When is the first frost in Oxbow, OR?
- The average first fall frost (32°F) is November 5. There is a 1-in-10 chance of frost by October 24, so tender plants are at risk from that point on.
- How long is the growing season in 97840?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 216 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.