Frost dates for 97722Diamond, OR
The average last spring frost in Diamond is May 29 and the average first fall frost is September 18, giving a typical growing season of about 113 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 29
- Average first fall frost
- Sep 18
- Growing season
- 113 days
Safer after Jun 17 (1-in-10 risk)
Possible by Sep 2 (1-in-10 risk)
Last frost typically in 208 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) | — | — | 81 days | 100% |
| Frost / freeze (32°F) | May 6 · May 29 · Jun 17 | Sep 2 · Sep 18 · Oct 3 | 113 days | 100% |
| Hard freeze (28°F) | Apr 20 · May 3 · May 24 | Sep 13 · Oct 1 · Oct 18 | 149 days | 100% |
Planting calendar for Diamond
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 | Apr 28 – Jul 4 |
| Tomatoes | Transplant outdoors | Jun 14 – May 29 |
| Peppers | Start seeds indoors | Apr 28 – May 29 |
| Peppers | Transplant outdoors | Jun 28 – Jul 29 |
| Eggplant | Start seeds indoors | May 15 – Jun 13 |
| Eggplant | Transplant outdoors | Jun 28 – Jul 29 |
| Cucumbers | Sow outdoors | Jun 28 – Jun 8 |
| Summer squash | Sow outdoors | Jun 14 – Jul 29 |
| Winter squash & pumpkins | Sow outdoors | Jun 28 – Jul 29 |
| Snap beans | Sow outdoors | Jun 14 – Jul 1 |
| Sweet corn | Sow outdoors | Jun 14 – May 29 |
| Watermelon & cantaloupe | Sow outdoors | Jun 28 – Jul 29 |
| Okra | Sow outdoors | Jun 21 – Jul 14 |
| Peas | Sow outdoors (spring) | Apr 28 – Jun 13 |
| Potatoes | Plant outdoors (spring) | Apr 28 – Jun 28 |
| Onions | Start seeds indoors (spring) | Mar 17 – Apr 13 |
| Onions | Transplant outdoors (spring) | May 15 – Jun 13 |
| Broccoli | Start seeds indoors (spring) | Apr 10 – May 14 |
| Broccoli | Transplant outdoors (spring) | May 15 – Jun 13 |
| Broccoli | Start seeds indoors (fall) | May 19 – May 29 |
| Broccoli | Transplant outdoors (fall) | Jun 18 – Jun 29 |
| Cabbage | Start seeds indoors (spring) | Mar 31 – Apr 28 |
| Cabbage | Transplant outdoors (spring) | Apr 28 – May 29 |
| Cabbage | Start seeds indoors (fall) | May 9 – Jun 8 |
| Cabbage | Transplant outdoors (fall) | Jun 8 – Jul 9 |
| Leaf lettuce | Sow outdoors (spring) | Apr 28 – Jul 14 |
| Leaf lettuce | Sow outdoors (fall) | Jun 8 – Jul 25 |
| Spinach | Sow outdoors (spring) | Apr 21 – Jun 4 |
| Spinach | Sow outdoors (fall) | Jun 25 – Jul 30 |
| Radishes | Sow outdoors (spring) | Apr 28 – Jun 18 |
| Radishes | Sow outdoors (fall) | Jun 8 – Aug 9 |
| Kale | Sow outdoors (spring) | May 15 – Jun 4 |
| Kale | Sow outdoors (fall) | Jun 1 – Jul 9 |
| Carrots | Sow outdoors (spring) | May 29 – Jul 14 |
| Carrots | Sow outdoors (fall) | May 9 – Jun 24 |
| Garlic | Plant outdoors (fall) | Sep 8 – Oct 9 |
Where these dates come from
ZIP code 97722 is matched to the NOAA station Malheur Refuge Hq, OR, 37 km away, at 4,118 ft elevation (567 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Malheur Refuge Hq, OR (used) | 4,118 ft | May 29 | Sep 18 |
| O O Rch, OR | 4,136 ft | Jun 11 | Sep 6 |
| Riverside 7 Ssw, OR | 3,380 ft | Jun 7 | Sep 6 |
| Burns Muni Ap, OR | 4,140 ft | Jun 11 | Sep 6 |
Frost dates near Diamond
- Princeton, OR 97721 · last Jun 11, first Sep 6
- Frenchglen, OR 97736 · last May 10, first Oct 7
- Crane, OR 97732 · last Jun 11, first Sep 6
- Burns, OR 97720 · last Jun 11, first Sep 6
- Hines, OR 97738 · last Jun 11, first Sep 6
- Riverside, OR 97917 · last Jun 7, first Sep 6
- Fields, OR 97710 · last May 10, first Oct 7
- Arock, OR 97902 · last Jun 11, first Sep 10
Frequently asked questions
- When is the last frost in Diamond, OR?
- For ZIP code 97722, the average last spring frost (32°F) is May 29, based on NOAA 1991-2020 climate normals for the Malheur Refuge Hq, OR weather station. There is a 1-in-10 chance of a frost after June 17.
- When is the first frost in Diamond, OR?
- The average first fall frost (32°F) is September 18. There is a 1-in-10 chance of frost by September 2, so tender plants are at risk from that point on.
- How long is the growing season in 97722?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 113 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.