Frost dates for 98355Mineral, WA
The average last spring frost in Mineral is April 18 and the average first fall frost is October 31, giving a typical growing season of about 196 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 18
- Average first fall frost
- Oct 31
- Growing season
- 196 days
Safer after May 10 (1-in-10 risk)
Possible by Oct 8 (1-in-10 risk)
First frost typically in 2 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 21 · May 6 · May 26 | Sep 26 · Oct 12 · Nov 1 | 157 days | 100% |
| Frost / freeze (32°F) | Mar 28 · Apr 18 · May 10 | Oct 8 · Oct 31 · Nov 21 | 196 days | 100% |
| Hard freeze (28°F) | Feb 13 · Mar 15 · Apr 11 | Oct 30 · Nov 17 · Dec 11 | 247 days | 100% |
Planting calendar for Mineral
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 18 – May 24 |
| Tomatoes | Transplant outdoors | May 4 – Jul 11 |
| Peppers | Start seeds indoors | Mar 18 – Apr 18 |
| Peppers | Transplant outdoors | May 18 – Jun 18 |
| Eggplant | Start seeds indoors | Apr 4 – May 3 |
| Eggplant | Transplant outdoors | May 18 – Jun 18 |
| Cucumbers | Sow outdoors | May 18 – Jul 21 |
| Summer squash | Sow outdoors | May 4 – Jun 18 |
| Winter squash & pumpkins | Sow outdoors | May 18 – Jun 18 |
| Snap beans | Sow outdoors | May 4 – Aug 13 |
| Sweet corn | Sow outdoors | May 4 – Jul 11 |
| Watermelon & cantaloupe | Sow outdoors | May 18 – Jun 18 |
| Okra | Sow outdoors | May 11 – Jun 3 |
| Peas | Sow outdoors (spring) | Mar 18 – May 3 |
| Potatoes | Plant outdoors (spring) | Mar 18 – May 18 |
| Onions | Start seeds indoors (spring) | Feb 4 – Mar 3 |
| Onions | Transplant outdoors (spring) | Apr 4 – May 3 |
| Broccoli | Start seeds indoors (spring) | Feb 28 – Apr 3 |
| Broccoli | Transplant outdoors (spring) | Apr 4 – May 3 |
| Broccoli | Start seeds indoors (fall) | Jul 1 – Jul 11 |
| Broccoli | Transplant outdoors (fall) | Jul 31 – Aug 11 |
| Cabbage | Start seeds indoors (spring) | Feb 18 – Mar 18 |
| Cabbage | Transplant outdoors (spring) | Mar 18 – Apr 18 |
| Cabbage | Start seeds indoors (fall) | Jun 21 – Jul 21 |
| Cabbage | Transplant outdoors (fall) | Jul 21 – Aug 21 |
| Leaf lettuce | Sow outdoors (spring) | Mar 18 – Jun 3 |
| Leaf lettuce | Sow outdoors (fall) | Jul 21 – Sep 6 |
| Spinach | Sow outdoors (spring) | Mar 11 – Apr 24 |
| Spinach | Sow outdoors (fall) | Aug 7 – Sep 11 |
| Radishes | Sow outdoors (spring) | Mar 18 – May 8 |
| Radishes | Sow outdoors (fall) | Jul 21 – Sep 21 |
| Kale | Sow outdoors (spring) | Apr 4 – Apr 24 |
| Kale | Sow outdoors (fall) | Jul 14 – Aug 21 |
| Carrots | Sow outdoors (spring) | Apr 18 – Jun 3 |
| Carrots | Sow outdoors (fall) | Jun 21 – Aug 6 |
| Garlic | Plant outdoors (fall) | Oct 21 – Nov 21 |
Where these dates come from
ZIP code 98355 is matched to the NOAA station Mud Mtn Dam, WA, 51.6 km away, at 1,308 ft elevation (214 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Mud Mtn Dam, WA (used) | 1,308 ft | Apr 18 | Oct 31 |
| Glenoma, WA | 840 ft | Apr 24 | Oct 15 |
| Longmire Rainier Nps, WA | 2,762 ft | May 22 | Oct 3 |
| Rainier Paradise Rs, WA | 5,427 ft | — | — |
Frost dates near Mineral
- Elbe, WA 98330 · last May 22, first Oct 3
- Ashford, WA 98304 · last May 22, first Oct 3
- La Grande, WA 98348 · last Apr 11, first Oct 30
- Morton, WA 98356 · last Apr 24, first Oct 15
- Eatonville, WA 98328 · last Apr 11, first Oct 30
- Glenoma, WA 98336 · last Apr 24, first Oct 15
- Silver Creek, WA 98585 · last Apr 5, first Oct 25
- Longmire, WA 98397 · last May 22, first Oct 3
Frequently asked questions
- When is the last frost in Mineral, WA?
- For ZIP code 98355, the average last spring frost (32°F) is April 18, based on NOAA 1991-2020 climate normals for the Mud Mtn Dam, WA weather station. There is a 1-in-10 chance of a frost after May 10.
- When is the first frost in Mineral, WA?
- The average first fall frost (32°F) is October 31. There is a 1-in-10 chance of frost by October 8, so tender plants are at risk from that point on.
- How long is the growing season in 98355?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 196 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.