Frost dates for 97030Gresham, OR
The average last spring frost in Gresham is March 16 and the average first fall frost is November 20, giving a typical growing season of about 250 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Mar 16
- Average first fall frost
- Nov 20
- Growing season
- 250 days
Safer after Apr 12 (1-in-10 risk)
Possible by Oct 30 (1-in-10 risk)
First frost typically in 21 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) | Mar 27 · Apr 19 · May 4 | Oct 11 · Oct 30 · Nov 22 | 198 days | 100% |
| Frost / freeze (32°F) | Feb 18 · Mar 16 · Apr 12 | Oct 30 · Nov 20 · Dec 17 | 250 days | 100% |
| Hard freeze (28°F) | Dec 27 · Feb 14 · Mar 10 | Nov 15 · Dec 15 · Feb 3 | 311 days | 93% |
Planting calendar for Gresham
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 13 – Apr 21 |
| Tomatoes | Transplant outdoors | Apr 1 – Jul 31 |
| Peppers | Start seeds indoors | Feb 13 – Mar 16 |
| Peppers | Transplant outdoors | Apr 15 – May 16 |
| Eggplant | Start seeds indoors | Mar 2 – Mar 31 |
| Eggplant | Transplant outdoors | Apr 15 – May 16 |
| Cucumbers | Sow outdoors | Apr 15 – Aug 10 |
| Summer squash | Sow outdoors | Apr 1 – May 16 |
| Winter squash & pumpkins | Sow outdoors | Apr 15 – May 16 |
| Snap beans | Sow outdoors | Apr 1 – Sep 2 |
| Sweet corn | Sow outdoors | Apr 1 – Jul 31 |
| Watermelon & cantaloupe | Sow outdoors | Apr 15 – May 16 |
| Okra | Sow outdoors | Apr 8 – May 1 |
| Peas | Sow outdoors (spring) | Feb 13 – Mar 31 |
| Potatoes | Plant outdoors (spring) | Feb 13 – Apr 15 |
| Onions | Start seeds indoors (spring) | Jan 2 – Jan 29 |
| Onions | Transplant outdoors (spring) | Mar 2 – Mar 31 |
| Broccoli | Start seeds indoors (spring) | Jan 26 – Mar 1 |
| Broccoli | Transplant outdoors (spring) | Mar 2 – Mar 31 |
| Broccoli | Start seeds indoors (fall) | Jul 21 – Jul 31 |
| Broccoli | Transplant outdoors (fall) | Aug 20 – Aug 31 |
| Cabbage | Start seeds indoors (spring) | Jan 16 – Feb 13 |
| Cabbage | Transplant outdoors (spring) | Feb 13 – Mar 16 |
| Cabbage | Start seeds indoors (fall) | Jul 11 – Aug 10 |
| Cabbage | Transplant outdoors (fall) | Aug 10 – Sep 10 |
| Leaf lettuce | Sow outdoors (spring) | Feb 13 – May 1 |
| Leaf lettuce | Sow outdoors (fall) | Aug 10 – Sep 26 |
| Spinach | Sow outdoors (spring) | Feb 6 – Mar 22 |
| Spinach | Sow outdoors (fall) | Aug 27 – Oct 1 |
| Radishes | Sow outdoors (spring) | Feb 13 – Apr 5 |
| Radishes | Sow outdoors (fall) | Aug 10 – Oct 11 |
| Kale | Sow outdoors (spring) | Mar 2 – Mar 22 |
| Kale | Sow outdoors (fall) | Aug 3 – Sep 10 |
| Carrots | Sow outdoors (spring) | Mar 16 – May 1 |
| Carrots | Sow outdoors (fall) | Jul 11 – Aug 26 |
| Garlic | Plant outdoors (fall) | Nov 10 – Dec 11 |
Where these dates come from
ZIP code 97030 is matched to the NOAA station Portland Troutdale Ap, OR, 4.1 km away, at 29 ft elevation (303 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Portland Troutdale Ap, OR (used) | 29 ft | Mar 16 | Nov 20 |
| Troutdale, OR | 33 ft | Mar 26 | Nov 17 |
| Portland Wfo, OR | 21 ft | Mar 13 | Nov 22 |
| Portland Intl Ap, OR | 19 ft | Mar 13 | Nov 19 |
Frost dates near Gresham
- Gresham, OR 97080 · last Mar 16, first Nov 20
- Troutdale, OR 97060 · last Mar 26, first Nov 17
- Fairview, OR 97024 · last Mar 16, first Nov 20
- Portland, OR 97233 · last Mar 13, first Nov 22
- Boring, OR 97009 · last Mar 27, first Nov 14
- Camas, WA 98607 · last Mar 26, first Nov 17
- Damascus, OR 97089 · last Mar 27, first Nov 14
- Happy Valley, OR 97086 · last Mar 18, first Nov 18
Frequently asked questions
- When is the last frost in Gresham, OR?
- For ZIP code 97030, the average last spring frost (32°F) is March 16, based on NOAA 1991-2020 climate normals for the Portland Troutdale Ap, OR weather station. There is a 1-in-10 chance of a frost after April 12.
- When is the first frost in Gresham, OR?
- The average first fall frost (32°F) is November 20. There is a 1-in-10 chance of frost by October 30, so tender plants are at risk from that point on.
- How long is the growing season in 97030?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 250 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.