Frost dates for 99118Curlew, WA
The average last spring frost in Curlew is May 6 and the average first fall frost is October 6, giving a typical growing season of about 151 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 6
- Average first fall frost
- Oct 6
- Growing season
- 151 days
Safer after May 25 (1-in-10 risk)
Possible by Sep 24 (1-in-10 risk)
Last frost typically in 190 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 9 · May 25 · Jun 15 | Sep 12 · Sep 25 · Oct 6 | 120 days | 100% |
| Frost / freeze (32°F) | Apr 23 · May 6 · May 25 | Sep 24 · Oct 6 · Oct 18 | 151 days | 100% |
| Hard freeze (28°F) | Apr 4 · Apr 19 · May 5 | Oct 4 · Oct 18 · Oct 31 | 181 days | 100% |
Planting calendar for Curlew
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 5 – Jun 11 |
| Tomatoes | Transplant outdoors | May 22 – Jun 16 |
| Peppers | Start seeds indoors | Apr 5 – May 6 |
| Peppers | Transplant outdoors | Jun 5 – Jul 6 |
| Eggplant | Start seeds indoors | Apr 22 – May 21 |
| Eggplant | Transplant outdoors | Jun 5 – Jul 6 |
| Cucumbers | Sow outdoors | Jun 5 – Jun 26 |
| Summer squash | Sow outdoors | May 22 – Jul 6 |
| Winter squash & pumpkins | Sow outdoors | Jun 5 – Jul 6 |
| Snap beans | Sow outdoors | May 22 – Jul 19 |
| Sweet corn | Sow outdoors | May 22 – Jun 16 |
| Watermelon & cantaloupe | Sow outdoors | Jun 5 – Jul 6 |
| Okra | Sow outdoors | May 29 – Jun 21 |
| Peas | Sow outdoors (spring) | Apr 5 – May 21 |
| Potatoes | Plant outdoors (spring) | Apr 5 – Jun 5 |
| Onions | Start seeds indoors (spring) | Feb 22 – Mar 21 |
| Onions | Transplant outdoors (spring) | Apr 22 – May 21 |
| Broccoli | Start seeds indoors (spring) | Mar 18 – Apr 21 |
| Broccoli | Transplant outdoors (spring) | Apr 22 – May 21 |
| Broccoli | Start seeds indoors (fall) | Jun 6 – Jun 16 |
| Broccoli | Transplant outdoors (fall) | Jul 6 – Jul 17 |
| Cabbage | Start seeds indoors (spring) | Mar 8 – Apr 5 |
| Cabbage | Transplant outdoors (spring) | Apr 5 – May 6 |
| Cabbage | Start seeds indoors (fall) | May 27 – Jun 26 |
| Cabbage | Transplant outdoors (fall) | Jun 26 – Jul 27 |
| Leaf lettuce | Sow outdoors (spring) | Apr 5 – Jun 21 |
| Leaf lettuce | Sow outdoors (fall) | Jun 26 – Aug 12 |
| Spinach | Sow outdoors (spring) | Mar 29 – May 12 |
| Spinach | Sow outdoors (fall) | Jul 13 – Aug 17 |
| Radishes | Sow outdoors (spring) | Apr 5 – May 26 |
| Radishes | Sow outdoors (fall) | Jun 26 – Aug 27 |
| Kale | Sow outdoors (spring) | Apr 22 – May 12 |
| Kale | Sow outdoors (fall) | Jun 19 – Jul 27 |
| Carrots | Sow outdoors (spring) | May 6 – Jun 21 |
| Carrots | Sow outdoors (fall) | May 27 – Jul 12 |
| Garlic | Plant outdoors (fall) | Sep 26 – Oct 27 |
Where these dates come from
ZIP code 99118 is matched to the NOAA station Tonasket 11Ne, WA, 46.7 km away, at 3,434 ft elevation (15 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Tonasket 11Ne, WA (used) | 3,434 ft | May 6 | Oct 6 |
| Republic, WA | 2,555 ft | May 30 | Sep 10 |
| Tonasket 4 Nne, WA | 960 ft | Apr 26 | Oct 10 |
| Northport, WA | 1,497 ft | May 8 | Oct 1 |
Frost dates near Curlew
- Malo, WA 99150 · last May 30, first Sep 10
- Danville, WA 99121 · last May 30, first Sep 10
- Wauconda, WA 98859 · last May 6, first Oct 6
- Republic, WA 99166 · last May 30, first Sep 10
- Laurier, WA 99146 · last May 8, first Oct 1
- Orient, WA 99160 · last May 8, first Oct 1
- Boyds, WA 99107 · last May 8, first Oct 1
- Marcus, WA 99151 · last May 2, first Oct 2
Frequently asked questions
- When is the last frost in Curlew, WA?
- For ZIP code 99118, the average last spring frost (32°F) is May 6, based on NOAA 1991-2020 climate normals for the Tonasket 11Ne, WA weather station. There is a 1-in-10 chance of a frost after May 25.
- When is the first frost in Curlew, WA?
- The average first fall frost (32°F) is October 6. There is a 1-in-10 chance of frost by September 24, so tender plants are at risk from that point on.
- How long is the growing season in 99118?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 151 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.