Frost dates for 99136Hay, WA
The average last spring frost in Hay is May 13 and the average first fall frost is September 26, giving a typical growing season of about 133 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 13
- Average first fall frost
- Sep 26
- Growing season
- 133 days
Safer after Jun 1 (1-in-10 risk)
Possible by Sep 8 (1-in-10 risk)
Last frost typically in 192 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 16 · Jun 4 · Jul 4 | Aug 29 · Sep 12 · Sep 29 | 98 days | 100% |
| Frost / freeze (32°F) | Apr 28 · May 13 · Jun 1 | Sep 8 · Sep 26 · Oct 11 | 133 days | 100% |
| Hard freeze (28°F) | Apr 9 · Apr 29 · May 15 | Sep 24 · Oct 7 · Oct 26 | 160 days | 100% |
Planting calendar for Hay
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 6 |
| 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 16 |
| Summer squash | Sow outdoors | May 29 – Jul 13 |
| Winter squash & pumpkins | Sow outdoors | Jun 12 – Jul 13 |
| Snap beans | Sow outdoors | May 29 – Jul 9 |
| Sweet corn | Sow outdoors | May 29 – Jun 6 |
| 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) | May 27 – Jun 6 |
| Broccoli | Transplant outdoors (fall) | Jun 26 – Jul 7 |
| Cabbage | Start seeds indoors (spring) | Mar 15 – Apr 12 |
| Cabbage | Transplant outdoors (spring) | Apr 12 – May 13 |
| Cabbage | Start seeds indoors (fall) | May 17 – Jun 16 |
| Cabbage | Transplant outdoors (fall) | Jun 16 – Jul 17 |
| Leaf lettuce | Sow outdoors (spring) | Apr 12 – Jun 28 |
| Leaf lettuce | Sow outdoors (fall) | Jun 16 – Aug 2 |
| Spinach | Sow outdoors (spring) | Apr 5 – May 19 |
| Spinach | Sow outdoors (fall) | Jul 3 – Aug 7 |
| Radishes | Sow outdoors (spring) | Apr 12 – Jun 2 |
| Radishes | Sow outdoors (fall) | Jun 16 – Aug 17 |
| Kale | Sow outdoors (spring) | Apr 29 – May 19 |
| Kale | Sow outdoors (fall) | Jun 9 – Jul 17 |
| Carrots | Sow outdoors (spring) | May 13 – Jun 28 |
| Carrots | Sow outdoors (fall) | May 17 – Jul 2 |
| Garlic | Plant outdoors (fall) | Sep 16 – Oct 17 |
Where these dates come from
ZIP code 99136 is matched to the NOAA station Lacrosse, WA, 14 km away, at 1,476 ft elevation (191 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Lacrosse, WA (used) | 1,476 ft | May 13 | Sep 26 |
| Pomeroy, WA | 1,934 ft | May 2 | Oct 4 |
| Dayton 1 Wsw, WA | 1,557 ft | Apr 28 | Oct 13 |
| St John, WA | 1,952 ft | Apr 29 | Oct 4 |
Frost dates near Hay
- Lacrosse, WA 99143 · last May 13, first Sep 26
- Hooper, WA 99333 · last May 13, first Sep 26
- Starbuck, WA 99359 · last Apr 28, first Oct 13
- Benge, WA 99105 · last May 13, first Sep 26
- Washtucna, WA 99371 · last May 13, first Sep 26
- Endicott, WA 99125 · last May 13, first Sep 26
- Pomeroy, WA 99347 · last May 2, first Oct 4
- Dayton, WA 99328 · last Apr 28, first Oct 13
Frequently asked questions
- When is the last frost in Hay, WA?
- For ZIP code 99136, the average last spring frost (32°F) is May 13, based on NOAA 1991-2020 climate normals for the Lacrosse, WA weather station. There is a 1-in-10 chance of a frost after June 1.
- When is the first frost in Hay, WA?
- The average first fall frost (32°F) is September 26. There is a 1-in-10 chance of frost by September 8, so tender plants are at risk from that point on.
- How long is the growing season in 99136?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 133 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.