Frost dates for 97886Weston, OR
The average last spring frost in Weston is May 12 and the average first fall frost is September 27, giving a typical growing season of about 135 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 12
- Average first fall frost
- Sep 27
- Growing season
- 135 days
Safer after Jun 2 (1-in-10 risk)
Possible by Sep 8 (1-in-10 risk)
Last frost typically in 192 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 17 · Jun 5 · Jun 25 | Aug 25 · Sep 9 · Sep 27 | 97 days | 100% |
| Frost / freeze (32°F) | Apr 28 · May 12 · Jun 2 | Sep 8 · Sep 27 · Oct 12 | 135 days | 100% |
| Hard freeze (28°F) | Apr 6 · Apr 27 · May 11 | Sep 24 · Oct 10 · Oct 28 | 168 days | 100% |
Planting calendar for Weston
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 7 |
| 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 17 |
| Summer squash | Sow outdoors | May 28 – Jul 12 |
| Winter squash & pumpkins | Sow outdoors | Jun 11 – Jul 12 |
| Snap beans | Sow outdoors | May 28 – Jul 10 |
| Sweet corn | Sow outdoors | May 28 – Jun 7 |
| 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) | May 28 – Jun 7 |
| Broccoli | Transplant outdoors (fall) | Jun 27 – Jul 8 |
| Cabbage | Start seeds indoors (spring) | Mar 14 – Apr 11 |
| Cabbage | Transplant outdoors (spring) | Apr 11 – May 12 |
| Cabbage | Start seeds indoors (fall) | May 18 – Jun 17 |
| Cabbage | Transplant outdoors (fall) | Jun 17 – Jul 18 |
| Leaf lettuce | Sow outdoors (spring) | Apr 11 – Jun 27 |
| Leaf lettuce | Sow outdoors (fall) | Jun 17 – Aug 3 |
| Spinach | Sow outdoors (spring) | Apr 4 – May 18 |
| Spinach | Sow outdoors (fall) | Jul 4 – Aug 8 |
| Radishes | Sow outdoors (spring) | Apr 11 – Jun 1 |
| Radishes | Sow outdoors (fall) | Jun 17 – Aug 18 |
| Kale | Sow outdoors (spring) | Apr 28 – May 18 |
| Kale | Sow outdoors (fall) | Jun 10 – Jul 18 |
| Carrots | Sow outdoors (spring) | May 12 – Jun 27 |
| Carrots | Sow outdoors (fall) | May 18 – Jul 3 |
| Garlic | Plant outdoors (fall) | Sep 17 – Oct 18 |
Where these dates come from
ZIP code 97886 is matched to the NOAA station Pendleton Branch Exp Stn, OR, 21.9 km away, at 1,487 ft elevation (954 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Pendleton Branch Exp Stn, OR (used) | 1,487 ft | May 12 | Sep 27 |
| Milton Freewater, OR | 970 ft | Mar 25 | Oct 29 |
| Whitman Mission, WA | 632 ft | May 2 | Oct 1 |
| Walla Walla Rgnl Ap, WA | 1,166 ft | Mar 27 | Oct 31 |
Frost dates near Weston
- Athena, OR 97813 · last May 12, first Sep 27
- Adams, OR 97810 · last May 12, first Sep 27
- Milton Freewater, OR 97862 · last Mar 25, first Oct 29
- College Place, WA 99324 · last May 2, first Oct 1
- Helix, OR 97835 · last May 12, first Sep 27
- Walla Walla, WA 99362 · last Mar 27, first Oct 31
- Meacham, OR 97859 · last —, first —
- Pendleton, OR 97801 · last Apr 14, first Oct 22
Frequently asked questions
- When is the last frost in Weston, OR?
- For ZIP code 97886, the average last spring frost (32°F) is May 12, based on NOAA 1991-2020 climate normals for the Pendleton Branch Exp Stn, OR weather station. There is a 1-in-10 chance of a frost after June 2.
- When is the first frost in Weston, OR?
- The average first fall frost (32°F) is September 27. There is a 1-in-10 chance of frost by September 8, so tender plants are at risk from that point on.
- How long is the growing season in 97886?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 135 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.