Frost dates for 98935Mabton, WA
The average last spring frost in Mabton is May 1 and the average first fall frost is October 6, giving a typical growing season of about 157 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 1
- Average first fall frost
- Oct 6
- Growing season
- 157 days
Safer after May 18 (1-in-10 risk)
Possible by Sep 25 (1-in-10 risk)
Last frost typically in 181 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 1 · May 16 · Jun 7 | Sep 10 · Sep 25 · Oct 7 | 127 days | 100% |
| Frost / freeze (32°F) | Apr 16 · May 1 · May 18 | Sep 25 · Oct 6 · Oct 22 | 157 days | 100% |
| Hard freeze (28°F) | Mar 28 · Apr 15 · May 1 | Oct 5 · Oct 19 · Nov 4 | 187 days | 100% |
Planting calendar for Mabton
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 31 – Jun 6 |
| Tomatoes | Transplant outdoors | May 17 – Jun 16 |
| Peppers | Start seeds indoors | Mar 31 – May 1 |
| Peppers | Transplant outdoors | May 31 – Jul 1 |
| Eggplant | Start seeds indoors | Apr 17 – May 16 |
| Eggplant | Transplant outdoors | May 31 – Jul 1 |
| Cucumbers | Sow outdoors | May 31 – Jun 26 |
| Summer squash | Sow outdoors | May 17 – Jul 1 |
| Winter squash & pumpkins | Sow outdoors | May 31 – Jul 1 |
| Snap beans | Sow outdoors | May 17 – Jul 19 |
| Sweet corn | Sow outdoors | May 17 – Jun 16 |
| Watermelon & cantaloupe | Sow outdoors | May 31 – Jul 1 |
| Okra | Sow outdoors | May 24 – Jun 16 |
| Peas | Sow outdoors (spring) | Mar 31 – May 16 |
| Potatoes | Plant outdoors (spring) | Mar 31 – May 31 |
| Onions | Start seeds indoors (spring) | Feb 17 – Mar 16 |
| Onions | Transplant outdoors (spring) | Apr 17 – May 16 |
| Broccoli | Start seeds indoors (spring) | Mar 13 – Apr 16 |
| Broccoli | Transplant outdoors (spring) | Apr 17 – May 16 |
| Broccoli | Start seeds indoors (fall) | Jun 6 – Jun 16 |
| Broccoli | Transplant outdoors (fall) | Jul 6 – Jul 17 |
| Cabbage | Start seeds indoors (spring) | Mar 3 – Mar 31 |
| Cabbage | Transplant outdoors (spring) | Mar 31 – May 1 |
| Cabbage | Start seeds indoors (fall) | May 27 – Jun 26 |
| Cabbage | Transplant outdoors (fall) | Jun 26 – Jul 27 |
| Leaf lettuce | Sow outdoors (spring) | Mar 31 – Jun 16 |
| Leaf lettuce | Sow outdoors (fall) | Jun 26 – Aug 12 |
| Spinach | Sow outdoors (spring) | Mar 24 – May 7 |
| Spinach | Sow outdoors (fall) | Jul 13 – Aug 17 |
| Radishes | Sow outdoors (spring) | Mar 31 – May 21 |
| Radishes | Sow outdoors (fall) | Jun 26 – Aug 27 |
| Kale | Sow outdoors (spring) | Apr 17 – May 7 |
| Kale | Sow outdoors (fall) | Jun 19 – Jul 27 |
| Carrots | Sow outdoors (spring) | May 1 – Jun 16 |
| Carrots | Sow outdoors (fall) | May 27 – Jul 12 |
| Garlic | Plant outdoors (fall) | Sep 26 – Oct 27 |
Where these dates come from
ZIP code 98935 is matched to the NOAA station Sunnyside, WA, 12.4 km away, at 747 ft elevation (22 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Sunnyside, WA (used) | 747 ft | May 1 | Oct 6 |
| Sunnyside #2, WA | 805 ft | Apr 30 | Oct 8 |
| Prosser, WA | 830 ft | Apr 14 | Oct 22 |
| Bickleton, WA | 3,015 ft | May 16 | Oct 9 |
Frost dates near Mabton
- Grandview, WA 98930 · last May 1, first Oct 6
- Sunnyside, WA 98944 · last May 1, first Oct 6
- Outlook, WA 98938 · last May 1, first Oct 6
- Prosser, WA 99350 · last Apr 14, first Oct 22
- Granger, WA 98932 · last May 1, first Oct 6
- Bickleton, WA 99322 · last May 16, first Oct 9
- Zillah, WA 98953 · last Apr 21, first Oct 15
- Toppenish, WA 98948 · last Apr 21, first Oct 15
Frequently asked questions
- When is the last frost in Mabton, WA?
- For ZIP code 98935, the average last spring frost (32°F) is May 1, based on NOAA 1991-2020 climate normals for the Sunnyside, WA weather station. There is a 1-in-10 chance of a frost after May 18.
- When is the first frost in Mabton, WA?
- The average first fall frost (32°F) is October 6. There is a 1-in-10 chance of frost by September 25, so tender plants are at risk from that point on.
- How long is the growing season in 98935?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 157 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.