Frost dates for 97039Moro, OR
The average last spring frost in Moro is May 12 and the average first fall frost is October 4, giving a typical growing season of about 143 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 12
- Average first fall frost
- Oct 4
- Growing season
- 143 days
Safer after May 31 (1-in-10 risk)
Possible by Sep 16 (1-in-10 risk)
Last frost typically in 193 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) | May 16 · Jun 5 · Jun 30 | Aug 30 · Sep 19 · Oct 4 | 102 days | 100% |
| Frost / freeze (32°F) | Apr 27 · May 12 · May 31 | Sep 16 · Oct 4 · Oct 18 | 143 days | 100% |
| Hard freeze (28°F) | Apr 8 · Apr 26 · May 11 | Oct 1 · Oct 16 · Nov 2 | 173 days | 100% |
Planting calendar for Moro
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 11 – Jun 17 |
| Tomatoes | Transplant outdoors | May 28 – Jun 14 |
| Peppers | Start seeds indoors | Apr 11 – May 12 |
| Peppers | Transplant outdoors | Jun 11 – Jul 12 |
| Eggplant | Start seeds indoors | Apr 28 – May 27 |
| Eggplant | Transplant outdoors | Jun 11 – Jul 12 |
| Cucumbers | Sow outdoors | Jun 11 – Jun 24 |
| Summer squash | Sow outdoors | May 28 – Jul 12 |
| Winter squash & pumpkins | Sow outdoors | Jun 11 – Jul 12 |
| Snap beans | Sow outdoors | May 28 – Jul 17 |
| Sweet corn | Sow outdoors | May 28 – Jun 14 |
| Watermelon & cantaloupe | Sow outdoors | Jun 11 – Jul 12 |
| Okra | Sow outdoors | Jun 4 – Jun 27 |
| Peas | Sow outdoors (spring) | Apr 11 – May 27 |
| Potatoes | Plant outdoors (spring) | Apr 11 – Jun 11 |
| Onions | Start seeds indoors (spring) | Feb 28 – Mar 27 |
| Onions | Transplant outdoors (spring) | Apr 28 – May 27 |
| Broccoli | Start seeds indoors (spring) | Mar 24 – Apr 27 |
| Broccoli | Transplant outdoors (spring) | Apr 28 – May 27 |
| Broccoli | Start seeds indoors (fall) | Jun 4 – Jun 14 |
| Broccoli | Transplant outdoors (fall) | Jul 4 – Jul 15 |
| Cabbage | Start seeds indoors (spring) | Mar 14 – Apr 11 |
| Cabbage | Transplant outdoors (spring) | Apr 11 – May 12 |
| Cabbage | Start seeds indoors (fall) | May 25 – Jun 24 |
| Cabbage | Transplant outdoors (fall) | Jun 24 – Jul 25 |
| Leaf lettuce | Sow outdoors (spring) | Apr 11 – Jun 27 |
| Leaf lettuce | Sow outdoors (fall) | Jun 24 – Aug 10 |
| Spinach | Sow outdoors (spring) | Apr 4 – May 18 |
| Spinach | Sow outdoors (fall) | Jul 11 – Aug 15 |
| Radishes | Sow outdoors (spring) | Apr 11 – Jun 1 |
| Radishes | Sow outdoors (fall) | Jun 24 – Aug 25 |
| Kale | Sow outdoors (spring) | Apr 28 – May 18 |
| Kale | Sow outdoors (fall) | Jun 17 – Jul 25 |
| Carrots | Sow outdoors (spring) | May 12 – Jun 27 |
| Carrots | Sow outdoors (fall) | May 25 – Jul 10 |
| Garlic | Plant outdoors (fall) | Sep 24 – Oct 25 |
Where these dates come from
ZIP code 97039 is matched to the NOAA station Moro, OR, 2.2 km away, at 1,870 ft elevation (197 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Moro, OR (used) | 1,870 ft | May 12 | Oct 4 |
| Kent, OR | 2,710 ft | May 15 | Oct 11 |
| Dufur, OR | 1,330 ft | May 12 | Oct 7 |
| Goldendale, WA | 1,640 ft | May 19 | Sep 25 |
Frost dates near Moro
- Wasco, OR 97065 · last May 12, first Oct 4
- Grass Valley, OR 97029 · last May 15, first Oct 11
- Rufus, OR 97050 · last Apr 11, first Oct 26
- Wishram, WA 98673 · last Apr 11, first Oct 26
- Centerville, WA 98613 · last May 19, first Sep 25
- Dufur, OR 97021 · last May 12, first Oct 4
- Mikkalo, OR 97861 · last May 12, first Oct 4
- Goldendale, WA 98620 · last May 19, first Sep 25
Frequently asked questions
- When is the last frost in Moro, OR?
- For ZIP code 97039, the average last spring frost (32°F) is May 12, based on NOAA 1991-2020 climate normals for the Moro, OR weather station. There is a 1-in-10 chance of a frost after May 31.
- When is the first frost in Moro, OR?
- The average first fall frost (32°F) is October 4. There is a 1-in-10 chance of frost by September 16, so tender plants are at risk from that point on.
- How long is the growing season in 97039?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 143 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.