Frost dates for 97424Cottage Grove, OR
The average last spring frost in Cottage Grove is April 12 and the average first fall frost is November 1, giving a typical growing season of about 205 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 12
- Average first fall frost
- Nov 1
- Growing season
- 205 days
Safer after May 4 (1-in-10 risk)
Possible by Oct 16 (1-in-10 risk)
First frost typically in 0 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 19 · May 4 · May 20 | Oct 1 · Oct 18 · Nov 4 | 165 days | 100% |
| Frost / freeze (32°F) | Mar 18 · Apr 12 · May 4 | Oct 16 · Nov 1 · Nov 23 | 205 days | 100% |
| Hard freeze (28°F) | Feb 4 · Mar 10 · Apr 6 | Oct 28 · Nov 21 · Dec 20 | 256 days | 100% |
Planting calendar for Cottage Grove
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 | Mar 12 – May 18 |
| Tomatoes | Transplant outdoors | Apr 28 – Jul 12 |
| Peppers | Start seeds indoors | Mar 12 – Apr 12 |
| Peppers | Transplant outdoors | May 12 – Jun 12 |
| Eggplant | Start seeds indoors | Mar 29 – Apr 27 |
| Eggplant | Transplant outdoors | May 12 – Jun 12 |
| Cucumbers | Sow outdoors | May 12 – Jul 22 |
| Summer squash | Sow outdoors | Apr 28 – Jun 12 |
| Winter squash & pumpkins | Sow outdoors | May 12 – Jun 12 |
| Snap beans | Sow outdoors | Apr 28 – Aug 14 |
| Sweet corn | Sow outdoors | Apr 28 – Jul 12 |
| Watermelon & cantaloupe | Sow outdoors | May 12 – Jun 12 |
| Okra | Sow outdoors | May 5 – May 28 |
| Peas | Sow outdoors (spring) | Mar 12 – Apr 27 |
| Potatoes | Plant outdoors (spring) | Mar 12 – May 12 |
| Onions | Start seeds indoors (spring) | Jan 29 – Feb 25 |
| Onions | Transplant outdoors (spring) | Mar 29 – Apr 27 |
| Broccoli | Start seeds indoors (spring) | Feb 22 – Mar 28 |
| Broccoli | Transplant outdoors (spring) | Mar 29 – Apr 27 |
| Broccoli | Start seeds indoors (fall) | Jul 2 – Jul 12 |
| Broccoli | Transplant outdoors (fall) | Aug 1 – Aug 12 |
| Cabbage | Start seeds indoors (spring) | Feb 12 – Mar 12 |
| Cabbage | Transplant outdoors (spring) | Mar 12 – Apr 12 |
| Cabbage | Start seeds indoors (fall) | Jun 22 – Jul 22 |
| Cabbage | Transplant outdoors (fall) | Jul 22 – Aug 22 |
| Leaf lettuce | Sow outdoors (spring) | Mar 12 – May 28 |
| Leaf lettuce | Sow outdoors (fall) | Jul 22 – Sep 7 |
| Spinach | Sow outdoors (spring) | Mar 5 – Apr 18 |
| Spinach | Sow outdoors (fall) | Aug 8 – Sep 12 |
| Radishes | Sow outdoors (spring) | Mar 12 – May 2 |
| Radishes | Sow outdoors (fall) | Jul 22 – Sep 22 |
| Kale | Sow outdoors (spring) | Mar 29 – Apr 18 |
| Kale | Sow outdoors (fall) | Jul 15 – Aug 22 |
| Carrots | Sow outdoors (spring) | Apr 12 – May 28 |
| Carrots | Sow outdoors (fall) | Jun 22 – Aug 7 |
| Garlic | Plant outdoors (fall) | Oct 22 – Nov 22 |
Where these dates come from
ZIP code 97424 is matched to the NOAA station Cottage Grove Dam, OR, 7.4 km away, at 831 ft elevation (61 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Cottage Grove Dam, OR (used) | 831 ft | Apr 12 | Nov 1 |
| Cottage Grove 2E, OR | 595 ft | Apr 24 | Oct 25 |
| Dorena, OR | 820 ft | Apr 16 | Oct 28 |
| Drain, OR | 292 ft | Apr 16 | Oct 25 |
Frost dates near Cottage Grove
- Creswell, OR 97426 · last Apr 16, first Oct 28
- Dorena, OR 97434 · last Apr 16, first Oct 28
- Lorane, OR 97451 · last Apr 24, first Oct 25
- Pleasant Hill, OR 97455 · last Mar 7, first Nov 27
- Drain, OR 97435 · last Apr 16, first Oct 25
- Dexter, OR 97431 · last Mar 7, first Nov 27
- Eugene, OR 97405 · last Mar 7, first Nov 27
- Lowell, OR 97452 · last Mar 7, first Nov 27
Frequently asked questions
- When is the last frost in Cottage Grove, OR?
- For ZIP code 97424, the average last spring frost (32°F) is April 12, based on NOAA 1991-2020 climate normals for the Cottage Grove Dam, OR weather station. There is a 1-in-10 chance of a frost after May 4.
- When is the first frost in Cottage Grove, OR?
- The average first fall frost (32°F) is November 1. There is a 1-in-10 chance of frost by October 16, so tender plants are at risk from that point on.
- How long is the growing season in 97424?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 205 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.