Frost dates for 97347Grand Ronde, OR
The average last spring frost in Grand Ronde is April 18 and the average first fall frost is November 7, giving a typical growing season of about 202 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 18
- Average first fall frost
- Nov 7
- Growing season
- 202 days
Safer after May 6 (1-in-10 risk)
Possible by Oct 21 (1-in-10 risk)
First frost typically in 7 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 26 · May 9 · May 29 | Oct 2 · Oct 21 · Nov 5 | 160 days | 100% |
| Frost / freeze (32°F) | Mar 27 · Apr 18 · May 6 | Oct 21 · Nov 7 · Nov 24 | 202 days | 100% |
| Hard freeze (28°F) | Feb 15 · Mar 13 · Apr 5 | Nov 3 · Nov 23 · Dec 20 | 252 days | 100% |
Planting calendar for Grand Ronde
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 18 – May 24 |
| Tomatoes | Transplant outdoors | May 4 – Jul 18 |
| Peppers | Start seeds indoors | Mar 18 – Apr 18 |
| Peppers | Transplant outdoors | May 18 – Jun 18 |
| Eggplant | Start seeds indoors | Apr 4 – May 3 |
| Eggplant | Transplant outdoors | May 18 – Jun 18 |
| Cucumbers | Sow outdoors | May 18 – Jul 28 |
| Summer squash | Sow outdoors | May 4 – Jun 18 |
| Winter squash & pumpkins | Sow outdoors | May 18 – Jun 18 |
| Snap beans | Sow outdoors | May 4 – Aug 20 |
| Sweet corn | Sow outdoors | May 4 – Jul 18 |
| Watermelon & cantaloupe | Sow outdoors | May 18 – Jun 18 |
| Okra | Sow outdoors | May 11 – Jun 3 |
| Peas | Sow outdoors (spring) | Mar 18 – May 3 |
| Potatoes | Plant outdoors (spring) | Mar 18 – May 18 |
| Onions | Start seeds indoors (spring) | Feb 4 – Mar 3 |
| Onions | Transplant outdoors (spring) | Apr 4 – May 3 |
| Broccoli | Start seeds indoors (spring) | Feb 28 – Apr 3 |
| Broccoli | Transplant outdoors (spring) | Apr 4 – May 3 |
| Broccoli | Start seeds indoors (fall) | Jul 8 – Jul 18 |
| Broccoli | Transplant outdoors (fall) | Aug 7 – Aug 18 |
| Cabbage | Start seeds indoors (spring) | Feb 18 – Mar 18 |
| Cabbage | Transplant outdoors (spring) | Mar 18 – Apr 18 |
| Cabbage | Start seeds indoors (fall) | Jun 28 – Jul 28 |
| Cabbage | Transplant outdoors (fall) | Jul 28 – Aug 28 |
| Leaf lettuce | Sow outdoors (spring) | Mar 18 – Jun 3 |
| Leaf lettuce | Sow outdoors (fall) | Jul 28 – Sep 13 |
| Spinach | Sow outdoors (spring) | Mar 11 – Apr 24 |
| Spinach | Sow outdoors (fall) | Aug 14 – Sep 18 |
| Radishes | Sow outdoors (spring) | Mar 18 – May 8 |
| Radishes | Sow outdoors (fall) | Jul 28 – Sep 28 |
| Kale | Sow outdoors (spring) | Apr 4 – Apr 24 |
| Kale | Sow outdoors (fall) | Jul 21 – Aug 28 |
| Carrots | Sow outdoors (spring) | Apr 18 – Jun 3 |
| Carrots | Sow outdoors (fall) | Jun 28 – Aug 13 |
| Garlic | Plant outdoors (fall) | Oct 28 – Nov 28 |
Where these dates come from
ZIP code 97347 is matched to the NOAA station Falls City 2 Ssw, OR, 30.2 km away, at 690 ft elevation (175 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Falls City 2 Ssw, OR (used) | 690 ft | Apr 18 | Nov 7 |
| Laurel Mtn, OR | 3,589 ft | May 20 | Oct 23 |
| Otis 2 Ne, OR | 150 ft | Apr 4 | Nov 16 |
| Cloverdale, OR | 12 ft | Mar 17 | Nov 22 |
Frost dates near Grand Ronde
- Willamina, OR 97396 · last Apr 16, first Nov 1
- Sheridan, OR 97378 · last Apr 16, first Nov 1
- Hebo, OR 97122 · last Mar 17, first Nov 22
- Neskowin, OR 97149 · last Apr 4, first Nov 16
- Otis, OR 97368 · last Apr 4, first Nov 16
- Beaver, OR 97108 · last Mar 17, first Nov 22
- Falls City, OR 97344 · last Apr 18, first Nov 7
- Cloverdale, OR 97112 · last Mar 17, first Nov 22
Frequently asked questions
- When is the last frost in Grand Ronde, OR?
- For ZIP code 97347, the average last spring frost (32°F) is April 18, based on NOAA 1991-2020 climate normals for the Falls City 2 Ssw, OR weather station. There is a 1-in-10 chance of a frost after May 6.
- When is the first frost in Grand Ronde, OR?
- The average first fall frost (32°F) is November 7. There is a 1-in-10 chance of frost by October 21, so tender plants are at risk from that point on.
- How long is the growing season in 97347?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 202 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.