Frost dates for 97055Sandy, OR
The average last spring frost in Sandy is March 27 and the average first fall frost is November 18, giving a typical growing season of about 239 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Mar 27
- Average first fall frost
- Nov 18
- Growing season
- 239 days
Safer after Apr 20 (1-in-10 risk)
Possible by Oct 26 (1-in-10 risk)
First frost typically in 18 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 7 · Apr 26 · May 12 | Oct 12 · Oct 29 · Nov 18 | 186 days | 100% |
| Frost / freeze (32°F) | Feb 26 · Mar 27 · Apr 20 | Oct 26 · Nov 18 · Dec 10 | 239 days | 100% |
| Hard freeze (28°F) | Jan 2 · Feb 14 · Mar 12 | Nov 12 · Dec 9 · Jan 19 | 303 days | 97% |
Planting calendar for Sandy
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 | Feb 24 – May 2 |
| Tomatoes | Transplant outdoors | Apr 12 – Jul 29 |
| Peppers | Start seeds indoors | Feb 24 – Mar 27 |
| Peppers | Transplant outdoors | Apr 26 – May 27 |
| Eggplant | Start seeds indoors | Mar 13 – Apr 11 |
| Eggplant | Transplant outdoors | Apr 26 – May 27 |
| Cucumbers | Sow outdoors | Apr 26 – Aug 8 |
| Summer squash | Sow outdoors | Apr 12 – May 27 |
| Winter squash & pumpkins | Sow outdoors | Apr 26 – May 27 |
| Snap beans | Sow outdoors | Apr 12 – Aug 31 |
| Sweet corn | Sow outdoors | Apr 12 – Jul 29 |
| Watermelon & cantaloupe | Sow outdoors | Apr 26 – May 27 |
| Okra | Sow outdoors | Apr 19 – May 12 |
| Peas | Sow outdoors (spring) | Feb 24 – Apr 11 |
| Potatoes | Plant outdoors (spring) | Feb 24 – Apr 26 |
| Onions | Start seeds indoors (spring) | Jan 13 – Feb 9 |
| Onions | Transplant outdoors (spring) | Mar 13 – Apr 11 |
| Broccoli | Start seeds indoors (spring) | Feb 6 – Mar 12 |
| Broccoli | Transplant outdoors (spring) | Mar 13 – Apr 11 |
| Broccoli | Start seeds indoors (fall) | Jul 19 – Jul 29 |
| Broccoli | Transplant outdoors (fall) | Aug 18 – Aug 29 |
| Cabbage | Start seeds indoors (spring) | Jan 27 – Feb 24 |
| Cabbage | Transplant outdoors (spring) | Feb 24 – Mar 27 |
| Cabbage | Start seeds indoors (fall) | Jul 9 – Aug 8 |
| Cabbage | Transplant outdoors (fall) | Aug 8 – Sep 8 |
| Leaf lettuce | Sow outdoors (spring) | Feb 24 – May 12 |
| Leaf lettuce | Sow outdoors (fall) | Aug 8 – Sep 24 |
| Spinach | Sow outdoors (spring) | Feb 17 – Apr 2 |
| Spinach | Sow outdoors (fall) | Aug 25 – Sep 29 |
| Radishes | Sow outdoors (spring) | Feb 24 – Apr 16 |
| Radishes | Sow outdoors (fall) | Aug 8 – Oct 9 |
| Kale | Sow outdoors (spring) | Mar 13 – Apr 2 |
| Kale | Sow outdoors (fall) | Aug 1 – Sep 8 |
| Carrots | Sow outdoors (spring) | Mar 27 – May 12 |
| Carrots | Sow outdoors (fall) | Jul 9 – Aug 24 |
| Garlic | Plant outdoors (fall) | Nov 8 – Dec 9 |
Where these dates come from
ZIP code 97055 is matched to the NOAA station Headworks Portland Wtr B, OR, 9.4 km away, at 748 ft elevation (453 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Headworks Portland Wtr B, OR (used) | 748 ft | Mar 27 | Nov 18 |
| Estacada 2 Se, OR | 514 ft | Mar 27 | Nov 14 |
| Troutdale, OR | 33 ft | Mar 26 | Nov 17 |
| Portland Troutdale Ap, OR | 29 ft | Mar 16 | Nov 20 |
Frost dates near Sandy
- Eagle Creek, OR 97022 · last Mar 27, first Nov 14
- Estacada, OR 97023 · last Mar 27, first Nov 14
- Boring, OR 97009 · last Mar 27, first Nov 14
- Corbett, OR 97019 · last Mar 27, first Nov 18
- Brightwood, OR 97011 · last Apr 5, first Nov 8
- Gresham, OR 97080 · last Mar 16, first Nov 20
- Damascus, OR 97089 · last Mar 27, first Nov 14
- Troutdale, OR 97060 · last Mar 26, first Nov 17
Frequently asked questions
- When is the last frost in Sandy, OR?
- For ZIP code 97055, the average last spring frost (32°F) is March 27, based on NOAA 1991-2020 climate normals for the Headworks Portland Wtr B, OR weather station. There is a 1-in-10 chance of a frost after April 20.
- When is the first frost in Sandy, OR?
- The average first fall frost (32°F) is November 18. There is a 1-in-10 chance of frost by October 26, so tender plants are at risk from that point on.
- How long is the growing season in 97055?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 239 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.