Frost dates for 97121Hammond, OR
The average last spring frost in Hammond is March 26 and the average first fall frost is November 11, giving a typical growing season of about 232 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Mar 26
- Average first fall frost
- Nov 11
- Growing season
- 232 days
Safer after Apr 18 (1-in-10 risk)
Possible by Oct 22 (1-in-10 risk)
First frost typically in 11 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 3 · Apr 25 · May 10 | Oct 5 · Oct 23 · Nov 11 | 181 days | 100% |
| Frost / freeze (32°F) | Feb 27 · Mar 26 · Apr 18 | Oct 22 · Nov 11 · Dec 8 | 232 days | 100% |
| Hard freeze (28°F) | Dec 31 · Feb 18 · Mar 17 | Nov 9 · Dec 5 · Jan 30 | 299 days | 96% |
Planting calendar for Hammond
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 23 – May 1 |
| Tomatoes | Transplant outdoors | Apr 11 – Jul 22 |
| Peppers | Start seeds indoors | Feb 23 – Mar 26 |
| Peppers | Transplant outdoors | Apr 25 – May 26 |
| Eggplant | Start seeds indoors | Mar 12 – Apr 10 |
| Eggplant | Transplant outdoors | Apr 25 – May 26 |
| Cucumbers | Sow outdoors | Apr 25 – Aug 1 |
| Summer squash | Sow outdoors | Apr 11 – May 26 |
| Winter squash & pumpkins | Sow outdoors | Apr 25 – May 26 |
| Snap beans | Sow outdoors | Apr 11 – Aug 24 |
| Sweet corn | Sow outdoors | Apr 11 – Jul 22 |
| Watermelon & cantaloupe | Sow outdoors | Apr 25 – May 26 |
| Okra | Sow outdoors | Apr 18 – May 11 |
| Peas | Sow outdoors (spring) | Feb 23 – Apr 10 |
| Potatoes | Plant outdoors (spring) | Feb 23 – Apr 25 |
| Onions | Start seeds indoors (spring) | Jan 12 – Feb 8 |
| Onions | Transplant outdoors (spring) | Mar 12 – Apr 10 |
| Broccoli | Start seeds indoors (spring) | Feb 5 – Mar 11 |
| Broccoli | Transplant outdoors (spring) | Mar 12 – Apr 10 |
| Broccoli | Start seeds indoors (fall) | Jul 12 – Jul 22 |
| Broccoli | Transplant outdoors (fall) | Aug 11 – Aug 22 |
| Cabbage | Start seeds indoors (spring) | Jan 26 – Feb 23 |
| Cabbage | Transplant outdoors (spring) | Feb 23 – Mar 26 |
| Cabbage | Start seeds indoors (fall) | Jul 2 – Aug 1 |
| Cabbage | Transplant outdoors (fall) | Aug 1 – Sep 1 |
| Leaf lettuce | Sow outdoors (spring) | Feb 23 – May 11 |
| Leaf lettuce | Sow outdoors (fall) | Aug 1 – Sep 17 |
| Spinach | Sow outdoors (spring) | Feb 16 – Apr 1 |
| Spinach | Sow outdoors (fall) | Aug 18 – Sep 22 |
| Radishes | Sow outdoors (spring) | Feb 23 – Apr 15 |
| Radishes | Sow outdoors (fall) | Aug 1 – Oct 2 |
| Kale | Sow outdoors (spring) | Mar 12 – Apr 1 |
| Kale | Sow outdoors (fall) | Jul 25 – Sep 1 |
| Carrots | Sow outdoors (spring) | Mar 26 – May 11 |
| Carrots | Sow outdoors (fall) | Jul 2 – Aug 17 |
| Garlic | Plant outdoors (fall) | Nov 1 – Dec 2 |
Where these dates come from
ZIP code 97121 is matched to the NOAA station Astoria Rgnl Ap, OR, 7.1 km away, at 9 ft elevation (4 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Astoria Rgnl Ap, OR (used) | 9 ft | Mar 26 | Nov 11 |
| Ft Clatsop Natl Mem, OR | 42 ft | Mar 30 | Nov 18 |
| Long Beach Exp Stn, WA | 25 ft | Apr 6 | Oct 26 |
| Seaside, OR | 10 ft | Apr 2 | Nov 12 |
Frost dates near Hammond
- Warrenton, OR 97146 · last Mar 26, first Nov 11
- Chinook, WA 98614 · last Apr 6, first Oct 26
- Astoria, OR 97103 · last Mar 30, first Nov 18
- Ilwaco, WA 98624 · last Apr 6, first Oct 26
- Seaview, WA 98644 · last Apr 6, first Oct 26
- Naselle, WA 98638 · last Apr 6, first Oct 26
- Long Beach, WA 98631 · last Apr 6, first Oct 26
- Seaside, OR 97138 · last Apr 2, first Nov 12
Frequently asked questions
- When is the last frost in Hammond, OR?
- For ZIP code 97121, the average last spring frost (32°F) is March 26, based on NOAA 1991-2020 climate normals for the Astoria Rgnl Ap, OR weather station. There is a 1-in-10 chance of a frost after April 18.
- When is the first frost in Hammond, OR?
- The average first fall frost (32°F) is November 11. There is a 1-in-10 chance of frost by October 22, so tender plants are at risk from that point on.
- How long is the growing season in 97121?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 232 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.