Frost dates for 99122Davenport, WA
The average last spring frost in Davenport is June 6 and the average first fall frost is September 11, giving a typical growing season of about 94 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Jun 6
- Average first fall frost
- Sep 11
- Growing season
- 94 days
Safer after Jul 5 (1-in-10 risk)
Possible by Aug 26 (1-in-10 risk)
Last frost typically in 215 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) | — | — | 57 days | 100% |
| Frost / freeze (32°F) | May 13 · Jun 6 · Jul 5 | Aug 26 · Sep 11 · Sep 28 | 94 days | 100% |
| Hard freeze (28°F) | Apr 26 · May 11 · Jun 2 | Sep 9 · Sep 27 · Oct 11 | 137 days | 100% |
Planting calendar for Davenport
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 | May 6 – Jul 12 |
| Tomatoes | Transplant outdoors | Jun 22 – May 22 |
| Peppers | Start seeds indoors | May 6 – Jun 6 |
| Peppers | Transplant outdoors | Jul 6 – Aug 6 |
| Eggplant | Start seeds indoors | May 23 – Jun 21 |
| Eggplant | Transplant outdoors | Jul 6 – Aug 6 |
| Cucumbers | Sow outdoors | Jul 6 – Jun 1 |
| Summer squash | Sow outdoors | Jun 22 – Aug 6 |
| Winter squash & pumpkins | Sow outdoors | Jul 6 – Aug 6 |
| Snap beans | Sow outdoors | Jun 22 – Jun 24 |
| Sweet corn | Sow outdoors | Jun 22 – May 22 |
| Watermelon & cantaloupe | Sow outdoors | Jul 6 – Aug 6 |
| Okra | Sow outdoors | Jun 29 – Jul 22 |
| Peas | Sow outdoors (spring) | May 6 – Jun 21 |
| Potatoes | Plant outdoors (spring) | May 6 – Jul 6 |
| Onions | Start seeds indoors (spring) | Mar 25 – Apr 21 |
| Onions | Transplant outdoors (spring) | May 23 – Jun 21 |
| Broccoli | Start seeds indoors (spring) | Apr 18 – May 22 |
| Broccoli | Transplant outdoors (spring) | May 23 – Jun 21 |
| Broccoli | Start seeds indoors (fall) | May 12 – May 22 |
| Broccoli | Transplant outdoors (fall) | Jun 11 – Jun 22 |
| Cabbage | Start seeds indoors (spring) | Apr 8 – May 6 |
| Cabbage | Transplant outdoors (spring) | May 6 – Jun 6 |
| Cabbage | Start seeds indoors (fall) | May 2 – Jun 1 |
| Cabbage | Transplant outdoors (fall) | Jun 1 – Jul 2 |
| Leaf lettuce | Sow outdoors (spring) | May 6 – Jul 22 |
| Leaf lettuce | Sow outdoors (fall) | Jun 1 – Jul 18 |
| Spinach | Sow outdoors (spring) | Apr 29 – Jun 12 |
| Spinach | Sow outdoors (fall) | Jun 18 – Jul 23 |
| Radishes | Sow outdoors (spring) | May 6 – Jun 26 |
| Radishes | Sow outdoors (fall) | Jun 1 – Aug 2 |
| Kale | Sow outdoors (spring) | May 23 – Jun 12 |
| Kale | Sow outdoors (fall) | May 25 – Jul 2 |
| Carrots | Sow outdoors (spring) | Jun 6 – Jul 22 |
| Carrots | Sow outdoors (fall) | May 2 – Jun 17 |
| Garlic | Plant outdoors (fall) | Sep 1 – Oct 2 |
Where these dates come from
ZIP code 99122 is matched to the NOAA station Davenport, WA, 2.6 km away, at 2,369 ft elevation (98 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Davenport, WA (used) | 2,369 ft | Jun 6 | Sep 11 |
| Harrington, WA | 2,159 ft | May 31 | Sep 12 |
| Spokane Wfo, WA | 2,392 ft | May 10 | Sep 26 |
| Wilbur, WA | 2,262 ft | Jun 1 | Sep 22 |
Frost dates near Davenport
- Reardan, WA 99029 · last May 10, first Sep 26
- Wellpinit, WA 99040 · last Jun 6, first Sep 11
- Edwall, WA 99008 · last Jun 6, first Sep 11
- Harrington, WA 99134 · last May 31, first Sep 12
- Lincoln, WA 99147 · last Apr 22, first Oct 21
- Creston, WA 99117 · last Jun 1, first Sep 22
- Fruitland, WA 99129 · last Jun 6, first Sep 11
- Medical Lake, WA 99022 · last May 10, first Sep 26
Frequently asked questions
- When is the last frost in Davenport, WA?
- For ZIP code 99122, the average last spring frost (32°F) is June 6, based on NOAA 1991-2020 climate normals for the Davenport, WA weather station. There is a 1-in-10 chance of a frost after July 5.
- When is the first frost in Davenport, WA?
- The average first fall frost (32°F) is September 11. There is a 1-in-10 chance of frost by August 26, so tender plants are at risk from that point on.
- How long is the growing season in 99122?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 94 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.