Frost dates for 99181Valley, WA
The average last spring frost in Valley is May 16 and the average first fall frost is September 15, giving a typical growing season of about 120 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 16
- Average first fall frost
- Sep 15
- Growing season
- 120 days
Safer after Jun 7 (1-in-10 risk)
Possible by Sep 1 (1-in-10 risk)
Last frost typically in 202 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) | — | — | 79 days | 100% |
| Frost / freeze (32°F) | Apr 30 · May 16 · Jun 7 | Sep 1 · Sep 15 · Sep 29 | 120 days | 100% |
| Hard freeze (28°F) | Apr 12 · Apr 30 · May 14 | Sep 15 · Sep 28 · Oct 13 | 153 days | 100% |
Planting calendar for Valley
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 | Apr 15 – Jun 21 |
| Tomatoes | Transplant outdoors | Jun 1 – May 26 |
| Peppers | Start seeds indoors | Apr 15 – May 16 |
| Peppers | Transplant outdoors | Jun 15 – Jul 16 |
| Eggplant | Start seeds indoors | May 2 – May 31 |
| Eggplant | Transplant outdoors | Jun 15 – Jul 16 |
| Cucumbers | Sow outdoors | Jun 15 – Jun 5 |
| Summer squash | Sow outdoors | Jun 1 – Jul 16 |
| Winter squash & pumpkins | Sow outdoors | Jun 15 – Jul 16 |
| Snap beans | Sow outdoors | Jun 1 – Jun 28 |
| Sweet corn | Sow outdoors | Jun 1 – May 26 |
| Watermelon & cantaloupe | Sow outdoors | Jun 15 – Jul 16 |
| Okra | Sow outdoors | Jun 8 – Jul 1 |
| Peas | Sow outdoors (spring) | Apr 15 – May 31 |
| Potatoes | Plant outdoors (spring) | Apr 15 – Jun 15 |
| Onions | Start seeds indoors (spring) | Mar 4 – Mar 31 |
| Onions | Transplant outdoors (spring) | May 2 – May 31 |
| Broccoli | Start seeds indoors (spring) | Mar 28 – May 1 |
| Broccoli | Transplant outdoors (spring) | May 2 – May 31 |
| Broccoli | Start seeds indoors (fall) | May 16 – May 26 |
| Broccoli | Transplant outdoors (fall) | Jun 15 – Jun 26 |
| Cabbage | Start seeds indoors (spring) | Mar 18 – Apr 15 |
| Cabbage | Transplant outdoors (spring) | Apr 15 – May 16 |
| Cabbage | Start seeds indoors (fall) | May 6 – Jun 5 |
| Cabbage | Transplant outdoors (fall) | Jun 5 – Jul 6 |
| Leaf lettuce | Sow outdoors (spring) | Apr 15 – Jul 1 |
| Leaf lettuce | Sow outdoors (fall) | Jun 5 – Jul 22 |
| Spinach | Sow outdoors (spring) | Apr 8 – May 22 |
| Spinach | Sow outdoors (fall) | Jun 22 – Jul 27 |
| Radishes | Sow outdoors (spring) | Apr 15 – Jun 5 |
| Radishes | Sow outdoors (fall) | Jun 5 – Aug 6 |
| Kale | Sow outdoors (spring) | May 2 – May 22 |
| Kale | Sow outdoors (fall) | May 29 – Jul 6 |
| Carrots | Sow outdoors (spring) | May 16 – Jul 1 |
| Carrots | Sow outdoors (fall) | May 6 – Jun 21 |
| Garlic | Plant outdoors (fall) | Sep 5 – Oct 6 |
Where these dates come from
ZIP code 99181 is matched to the NOAA station Chewelah, WA, 15.4 km away, at 1,670 ft elevation (115 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Chewelah, WA (used) | 1,670 ft | May 16 | Sep 15 |
| Deer Park Ap, WA | 2,191 ft | May 22 | Sep 14 |
| Colville, WA | 1,554 ft | May 2 | Oct 2 |
| Spokane Wfo, WA | 2,392 ft | May 10 | Sep 26 |
Frost dates near Valley
- Loon Lake, WA 99148 · last May 22, first Sep 14
- Springdale, WA 99173 · last May 10, first Sep 26
- Chewelah, WA 99109 · last May 16, first Sep 15
- Clayton, WA 99110 · last May 22, first Sep 14
- Ford, WA 99013 · last May 16, first Sep 15
- Addy, WA 99101 · last May 16, first Sep 15
- Tumtum, WA 99034 · last May 10, first Sep 26
- Hunters, WA 99137 · last Jun 6, first Sep 11
Frequently asked questions
- When is the last frost in Valley, WA?
- For ZIP code 99181, the average last spring frost (32°F) is May 16, based on NOAA 1991-2020 climate normals for the Chewelah, WA weather station. There is a 1-in-10 chance of a frost after June 7.
- When is the first frost in Valley, WA?
- The average first fall frost (32°F) is September 15. There is a 1-in-10 chance of frost by September 1, so tender plants are at risk from that point on.
- How long is the growing season in 99181?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 120 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.