Frost dates for 99344Othello, WA
The average last spring frost in Othello is April 25 and the average first fall frost is October 15, giving a typical growing season of about 173 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 25
- Average first fall frost
- Oct 15
- Growing season
- 173 days
Safer after May 11 (1-in-10 risk)
Possible by Oct 2 (1-in-10 risk)
Last frost typically in 174 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 26 · May 10 · May 27 | Sep 22 · Oct 5 · Oct 18 | 146 days | 100% |
| Frost / freeze (32°F) | Apr 4 · Apr 25 · May 11 | Oct 2 · Oct 15 · Nov 1 | 173 days | 100% |
| Hard freeze (28°F) | Mar 7 · Apr 1 · Apr 25 | Oct 10 · Oct 28 · Nov 16 | 210 days | 100% |
Planting calendar for Othello
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 25 – May 31 |
| Tomatoes | Transplant outdoors | May 11 – Jun 25 |
| Peppers | Start seeds indoors | Mar 25 – Apr 25 |
| Peppers | Transplant outdoors | May 25 – Jun 25 |
| Eggplant | Start seeds indoors | Apr 11 – May 10 |
| Eggplant | Transplant outdoors | May 25 – Jun 25 |
| Cucumbers | Sow outdoors | May 25 – Jul 5 |
| Summer squash | Sow outdoors | May 11 – Jun 25 |
| Winter squash & pumpkins | Sow outdoors | May 25 – Jun 25 |
| Snap beans | Sow outdoors | May 11 – Jul 28 |
| Sweet corn | Sow outdoors | May 11 – Jun 25 |
| Watermelon & cantaloupe | Sow outdoors | May 25 – Jun 25 |
| Okra | Sow outdoors | May 18 – Jun 10 |
| Peas | Sow outdoors (spring) | Mar 25 – May 10 |
| Potatoes | Plant outdoors (spring) | Mar 25 – May 25 |
| Onions | Start seeds indoors (spring) | Feb 11 – Mar 10 |
| Onions | Transplant outdoors (spring) | Apr 11 – May 10 |
| Broccoli | Start seeds indoors (spring) | Mar 7 – Apr 10 |
| Broccoli | Transplant outdoors (spring) | Apr 11 – May 10 |
| Broccoli | Start seeds indoors (fall) | Jun 15 – Jun 25 |
| Broccoli | Transplant outdoors (fall) | Jul 15 – Jul 26 |
| Cabbage | Start seeds indoors (spring) | Feb 25 – Mar 25 |
| Cabbage | Transplant outdoors (spring) | Mar 25 – Apr 25 |
| Cabbage | Start seeds indoors (fall) | Jun 5 – Jul 5 |
| Cabbage | Transplant outdoors (fall) | Jul 5 – Aug 5 |
| Leaf lettuce | Sow outdoors (spring) | Mar 25 – Jun 10 |
| Leaf lettuce | Sow outdoors (fall) | Jul 5 – Aug 21 |
| Spinach | Sow outdoors (spring) | Mar 18 – May 1 |
| Spinach | Sow outdoors (fall) | Jul 22 – Aug 26 |
| Radishes | Sow outdoors (spring) | Mar 25 – May 15 |
| Radishes | Sow outdoors (fall) | Jul 5 – Sep 5 |
| Kale | Sow outdoors (spring) | Apr 11 – May 1 |
| Kale | Sow outdoors (fall) | Jun 28 – Aug 5 |
| Carrots | Sow outdoors (spring) | Apr 25 – Jun 10 |
| Carrots | Sow outdoors (fall) | Jun 5 – Jul 21 |
| Garlic | Plant outdoors (fall) | Oct 5 – Nov 5 |
Where these dates come from
ZIP code 99344 is matched to the NOAA station Hatton 9 Se, WA, 29.7 km away, at 1,505 ft elevation (166 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Hatton 9 Se, WA (used) | 1,505 ft | Apr 25 | Oct 15 |
| Connell 1 W, WA | 1,020 ft | Apr 30 | Oct 12 |
| Lind 3 Ne, WA | 1,630 ft | May 7 | Oct 4 |
| Moses Lake Grant Co Ap, WA | 1,196 ft | Apr 27 | Oct 8 |
Frost dates near Othello
- Warden, WA 98857 · last Apr 27, first Oct 8
- Connell, WA 99326 · last Apr 30, first Oct 12
- Lind, WA 99341 · last May 7, first Oct 4
- Mesa, WA 99343 · last Apr 21, first Oct 22
- Moses Lake, WA 98837 · last Apr 27, first Oct 8
- Kahlotus, WA 99335 · last Apr 25, first Oct 15
- Eltopia, WA 99330 · last Apr 21, first Oct 22
- Royal City, WA 99357 · last Apr 23, first Oct 12
Frequently asked questions
- When is the last frost in Othello, WA?
- For ZIP code 99344, the average last spring frost (32°F) is April 25, based on NOAA 1991-2020 climate normals for the Hatton 9 Se, WA weather station. There is a 1-in-10 chance of a frost after May 11.
- When is the first frost in Othello, WA?
- The average first fall frost (32°F) is October 15. There is a 1-in-10 chance of frost by October 2, so tender plants are at risk from that point on.
- How long is the growing season in 99344?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 173 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.