Frost dates for 98511Tumwater, WA
The average last spring frost in Tumwater is April 29 and the average first fall frost is October 14, giving a typical growing season of about 169 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 29
- Average first fall frost
- Oct 14
- Growing season
- 169 days
Safer after May 15 (1-in-10 risk)
Possible by Sep 28 (1-in-10 risk)
Last frost typically in 181 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 30 · May 15 · May 31 | Sep 12 · Sep 28 · Oct 14 | 135 days | 100% |
| Frost / freeze (32°F) | Apr 11 · Apr 29 · May 15 | Sep 28 · Oct 14 · Nov 1 | 169 days | 100% |
| Hard freeze (28°F) | Mar 12 · Apr 5 · Apr 29 | Oct 9 · Nov 1 · Nov 24 | 210 days | 100% |
Planting calendar for Tumwater
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 24 |
| 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 4 |
| Summer squash | Sow outdoors | May 15 – Jun 29 |
| Winter squash & pumpkins | Sow outdoors | May 29 – Jun 29 |
| Snap beans | Sow outdoors | May 15 – Jul 27 |
| Sweet corn | Sow outdoors | May 15 – Jun 24 |
| 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 14 – Jun 24 |
| Broccoli | Transplant outdoors (fall) | Jul 14 – Jul 25 |
| Cabbage | Start seeds indoors (spring) | Mar 1 – Mar 29 |
| Cabbage | Transplant outdoors (spring) | Mar 29 – Apr 29 |
| Cabbage | Start seeds indoors (fall) | Jun 4 – Jul 4 |
| Cabbage | Transplant outdoors (fall) | Jul 4 – Aug 4 |
| Leaf lettuce | Sow outdoors (spring) | Mar 29 – Jun 14 |
| Leaf lettuce | Sow outdoors (fall) | Jul 4 – Aug 20 |
| Spinach | Sow outdoors (spring) | Mar 22 – May 5 |
| Spinach | Sow outdoors (fall) | Jul 21 – Aug 25 |
| Radishes | Sow outdoors (spring) | Mar 29 – May 19 |
| Radishes | Sow outdoors (fall) | Jul 4 – Sep 4 |
| Kale | Sow outdoors (spring) | Apr 15 – May 5 |
| Kale | Sow outdoors (fall) | Jun 27 – Aug 4 |
| Carrots | Sow outdoors (spring) | Apr 29 – Jun 14 |
| Carrots | Sow outdoors (fall) | Jun 4 – Jul 20 |
| Garlic | Plant outdoors (fall) | Oct 4 – Nov 4 |
Where these dates come from
ZIP code 98511 is matched to the NOAA station Olympia Ap, WA, 9.6 km away, at 188 ft elevation (31 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Olympia Ap, WA (used) | 188 ft | Apr 29 | Oct 14 |
| Centralia, WA | 185 ft | Apr 22 | Oct 27 |
| Elma, WA | 70 ft | May 1 | Oct 14 |
| Shelton Sanderson Fld, WA | 271 ft | Apr 27 | Oct 16 |
Frost dates near Tumwater
- Olympia, WA 98512 · last Apr 29, first Oct 14
- Littlerock, WA 98556 · last Apr 29, first Oct 14
- Rochester, WA 98579 · last Apr 22, first Oct 27
- Tenino, WA 98589 · last Apr 29, first Oct 14
- Lacey, WA 98503 · last Apr 29, first Oct 14
- Mccleary, WA 98557 · last May 1, first Oct 14
- Oakville, WA 98568 · last May 1, first Oct 14
- Bucoda, WA 98530 · last Apr 22, first Oct 27
Frequently asked questions
- When is the last frost in Tumwater, WA?
- For ZIP code 98511, the average last spring frost (32°F) is April 29, based on NOAA 1991-2020 climate normals for the Olympia Ap, WA weather station. There is a 1-in-10 chance of a frost after May 15.
- When is the first frost in Tumwater, WA?
- The average first fall frost (32°F) is October 14. There is a 1-in-10 chance of frost by September 28, so tender plants are at risk from that point on.
- How long is the growing season in 98511?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 169 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.