Frost dates for 97345Foster, OR
The average last spring frost in Foster is April 29 and the average first fall frost is October 13, giving a typical growing season of about 167 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 29
- Average first fall frost
- Oct 13
- Growing season
- 167 days
Safer after May 17 (1-in-10 risk)
Possible by Sep 22 (1-in-10 risk)
Last frost typically in 179 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 2 · May 21 · Jun 12 | Aug 30 · Sep 21 · Oct 14 | 121 days | 100% |
| Frost / freeze (32°F) | Apr 5 · Apr 29 · May 17 | Sep 22 · Oct 13 · Nov 6 | 167 days | 100% |
| Hard freeze (28°F) | Feb 26 · Mar 30 · Apr 28 | Oct 12 · Nov 5 · Dec 4 | 220 days | 100% |
Planting calendar for Foster
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 29 – Jun 4 |
| Tomatoes | Transplant outdoors | May 15 – Jun 23 |
| Peppers | Start seeds indoors | Mar 29 – Apr 29 |
| Peppers | Transplant outdoors | May 29 – Jun 29 |
| Eggplant | Start seeds indoors | Apr 15 – May 14 |
| Eggplant | Transplant outdoors | May 29 – Jun 29 |
| Cucumbers | Sow outdoors | May 29 – Jul 3 |
| Summer squash | Sow outdoors | May 15 – Jun 29 |
| Winter squash & pumpkins | Sow outdoors | May 29 – Jun 29 |
| Snap beans | Sow outdoors | May 15 – Jul 26 |
| Sweet corn | Sow outdoors | May 15 – Jun 23 |
| Watermelon & cantaloupe | Sow outdoors | May 29 – Jun 29 |
| Okra | Sow outdoors | May 22 – Jun 14 |
| Peas | Sow outdoors (spring) | Mar 29 – May 14 |
| Potatoes | Plant outdoors (spring) | Mar 29 – May 29 |
| Onions | Start seeds indoors (spring) | Feb 15 – Mar 14 |
| Onions | Transplant outdoors (spring) | Apr 15 – May 14 |
| Broccoli | Start seeds indoors (spring) | Mar 11 – Apr 14 |
| Broccoli | Transplant outdoors (spring) | Apr 15 – May 14 |
| Broccoli | Start seeds indoors (fall) | Jun 13 – Jun 23 |
| Broccoli | Transplant outdoors (fall) | Jul 13 – Jul 24 |
| Cabbage | Start seeds indoors (spring) | Mar 1 – Mar 29 |
| Cabbage | Transplant outdoors (spring) | Mar 29 – Apr 29 |
| Cabbage | Start seeds indoors (fall) | Jun 3 – Jul 3 |
| Cabbage | Transplant outdoors (fall) | Jul 3 – Aug 3 |
| Leaf lettuce | Sow outdoors (spring) | Mar 29 – Jun 14 |
| Leaf lettuce | Sow outdoors (fall) | Jul 3 – Aug 19 |
| Spinach | Sow outdoors (spring) | Mar 22 – May 5 |
| Spinach | Sow outdoors (fall) | Jul 20 – Aug 24 |
| Radishes | Sow outdoors (spring) | Mar 29 – May 19 |
| Radishes | Sow outdoors (fall) | Jul 3 – Sep 3 |
| Kale | Sow outdoors (spring) | Apr 15 – May 5 |
| Kale | Sow outdoors (fall) | Jun 26 – Aug 3 |
| Carrots | Sow outdoors (spring) | Apr 29 – Jun 14 |
| Carrots | Sow outdoors (fall) | Jun 3 – Jul 19 |
| Garlic | Plant outdoors (fall) | Oct 3 – Nov 3 |
Where these dates come from
ZIP code 97345 is matched to the NOAA station Cascadia, OR, 5.1 km away, at 960 ft elevation (759 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Cascadia, OR (used) | 960 ft | Apr 29 | Oct 13 |
| Foster Dam, OR | 550 ft | Apr 12 | Oct 28 |
| Lacomb 3 Nne, OR | 520 ft | Apr 26 | Oct 24 |
| Lebanon, OR | 330 ft | Mar 14 | Nov 18 |
Frost dates near Foster
- Cascadia, OR 97329 · last Apr 29, first Oct 13
- Sweet Home, OR 97386 · last Apr 12, first Oct 28
- Crawfordsville, OR 97336 · last Apr 12, first Oct 28
- Vida, OR 97488 · last Apr 3, first Nov 11
- Walterville, OR 97489 · last Apr 3, first Nov 11
- Marcola, OR 97454 · last Apr 3, first Nov 11
- Lebanon, OR 97355 · last Apr 26, first Oct 24
- Brownsville, OR 97327 · last Apr 12, first Oct 28
Frequently asked questions
- When is the last frost in Foster, OR?
- For ZIP code 97345, the average last spring frost (32°F) is April 29, based on NOAA 1991-2020 climate normals for the Cascadia, OR weather station. There is a 1-in-10 chance of a frost after May 17.
- When is the first frost in Foster, OR?
- The average first fall frost (32°F) is October 13. There is a 1-in-10 chance of frost by September 22, so tender plants are at risk from that point on.
- How long is the growing season in 97345?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 167 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.