Frost dates for 98651Underwood, WA
The average last spring frost in Underwood is May 13 and the average first fall frost is October 3, giving a typical growing season of about 142 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 13
- Average first fall frost
- Oct 3
- Growing season
- 142 days
Safer after Jun 3 (1-in-10 risk)
Possible by Sep 15 (1-in-10 risk)
Last frost typically in 194 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 20 · Jun 8 · Jul 2 | Aug 26 · Sep 15 · Oct 2 | 96 days | 100% |
| Frost / freeze (32°F) | Apr 26 · May 13 · Jun 3 | Sep 15 · Oct 3 · Oct 19 | 142 days | 100% |
| Hard freeze (28°F) | Mar 28 · Apr 21 · May 9 | Oct 3 · Oct 20 · Nov 6 | 184 days | 100% |
Planting calendar for Underwood
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 12 – Jun 18 |
| Tomatoes | Transplant outdoors | May 29 – Jun 13 |
| Peppers | Start seeds indoors | Apr 12 – May 13 |
| Peppers | Transplant outdoors | Jun 12 – Jul 13 |
| Eggplant | Start seeds indoors | Apr 29 – May 28 |
| Eggplant | Transplant outdoors | Jun 12 – Jul 13 |
| Cucumbers | Sow outdoors | Jun 12 – Jun 23 |
| Summer squash | Sow outdoors | May 29 – Jul 13 |
| Winter squash & pumpkins | Sow outdoors | Jun 12 – Jul 13 |
| Snap beans | Sow outdoors | May 29 – Jul 16 |
| Sweet corn | Sow outdoors | May 29 – Jun 13 |
| Watermelon & cantaloupe | Sow outdoors | Jun 12 – Jul 13 |
| Okra | Sow outdoors | Jun 5 – Jun 28 |
| Peas | Sow outdoors (spring) | Apr 12 – May 28 |
| Potatoes | Plant outdoors (spring) | Apr 12 – Jun 12 |
| Onions | Start seeds indoors (spring) | Mar 1 – Mar 28 |
| Onions | Transplant outdoors (spring) | Apr 29 – May 28 |
| Broccoli | Start seeds indoors (spring) | Mar 25 – Apr 28 |
| Broccoli | Transplant outdoors (spring) | Apr 29 – May 28 |
| Broccoli | Start seeds indoors (fall) | Jun 3 – Jun 13 |
| Broccoli | Transplant outdoors (fall) | Jul 3 – Jul 14 |
| Cabbage | Start seeds indoors (spring) | Mar 15 – Apr 12 |
| Cabbage | Transplant outdoors (spring) | Apr 12 – May 13 |
| Cabbage | Start seeds indoors (fall) | May 24 – Jun 23 |
| Cabbage | Transplant outdoors (fall) | Jun 23 – Jul 24 |
| Leaf lettuce | Sow outdoors (spring) | Apr 12 – Jun 28 |
| Leaf lettuce | Sow outdoors (fall) | Jun 23 – Aug 9 |
| Spinach | Sow outdoors (spring) | Apr 5 – May 19 |
| Spinach | Sow outdoors (fall) | Jul 10 – Aug 14 |
| Radishes | Sow outdoors (spring) | Apr 12 – Jun 2 |
| Radishes | Sow outdoors (fall) | Jun 23 – Aug 24 |
| Kale | Sow outdoors (spring) | Apr 29 – May 19 |
| Kale | Sow outdoors (fall) | Jun 16 – Jul 24 |
| Carrots | Sow outdoors (spring) | May 13 – Jun 28 |
| Carrots | Sow outdoors (fall) | May 24 – Jul 9 |
| Garlic | Plant outdoors (fall) | Sep 23 – Oct 24 |
Where these dates come from
ZIP code 98651 is matched to the NOAA station Parkdale 1 Nne, OR, 22.9 km away, at 1,520 ft elevation (137 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Parkdale 1 Nne, OR (used) | 1,520 ft | May 13 | Oct 3 |
| Hood Rvr Exp Stn, OR | 500 ft | Apr 20 | Oct 13 |
| Snowden, WA | 2,415 ft | May 12 | Oct 11 |
| Cascade Locks, OR | 142 ft | Mar 24 | Nov 20 |
Frost dates near Underwood
- Bingen, WA 98605 · last May 2, first Oct 9
- Hood River, OR 97031 · last Apr 20, first Oct 13
- White Salmon, WA 98672 · last Apr 20, first Oct 13
- Husum, WA 98623 · last Apr 20, first Oct 13
- Odell, OR 97044 · last Apr 20, first Oct 13
- Carson, WA 98610 · last Apr 20, first Oct 13
- Mosier, OR 97040 · last Apr 20, first Oct 13
- Cascade Locks, OR 97014 · last Mar 14, first Nov 27
Frequently asked questions
- When is the last frost in Underwood, WA?
- For ZIP code 98651, the average last spring frost (32°F) is May 13, based on NOAA 1991-2020 climate normals for the Parkdale 1 Nne, OR weather station. There is a 1-in-10 chance of a frost after June 3.
- When is the first frost in Underwood, WA?
- The average first fall frost (32°F) is October 3. There is a 1-in-10 chance of frost by September 15, so tender plants are at risk from that point on.
- How long is the growing season in 98651?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 142 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.