Frost dates for 98943South Cle Elum, WA
The average last spring frost in South Cle Elum is May 13 and the average first fall frost is September 25, giving a typical growing season of about 132 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 13
- Average first fall frost
- Sep 25
- Growing season
- 132 days
Safer after Jun 1 (1-in-10 risk)
Possible by Sep 11 (1-in-10 risk)
Last frost typically in 200 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 13 · Jun 1 · Jun 19 | Aug 31 · Sep 11 · Sep 27 | 102 days | 100% |
| Frost / freeze (32°F) | Apr 29 · May 13 · Jun 1 | Sep 11 · Sep 25 · Oct 7 | 132 days | 100% |
| Hard freeze (28°F) | Apr 12 · Apr 28 · May 14 | Sep 20 · Oct 5 · Oct 23 | 159 days | 100% |
Planting calendar for South Cle Elum
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 5 |
| 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 15 |
| Summer squash | Sow outdoors | May 29 – Jul 13 |
| Winter squash & pumpkins | Sow outdoors | Jun 12 – Jul 13 |
| Snap beans | Sow outdoors | May 29 – Jul 8 |
| Sweet corn | Sow outdoors | May 29 – Jun 5 |
| 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 26 – Jun 5 |
| Broccoli | Transplant outdoors (fall) | Jun 25 – Jul 6 |
| Cabbage | Start seeds indoors (spring) | Mar 15 – Apr 12 |
| Cabbage | Transplant outdoors (spring) | Apr 12 – May 13 |
| Cabbage | Start seeds indoors (fall) | May 16 – Jun 15 |
| Cabbage | Transplant outdoors (fall) | Jun 15 – Jul 16 |
| Leaf lettuce | Sow outdoors (spring) | Apr 12 – Jun 28 |
| Leaf lettuce | Sow outdoors (fall) | Jun 15 – Aug 1 |
| Spinach | Sow outdoors (spring) | Apr 5 – May 19 |
| Spinach | Sow outdoors (fall) | Jul 2 – Aug 6 |
| Radishes | Sow outdoors (spring) | Apr 12 – Jun 2 |
| Radishes | Sow outdoors (fall) | Jun 15 – Aug 16 |
| Kale | Sow outdoors (spring) | Apr 29 – May 19 |
| Kale | Sow outdoors (fall) | Jun 8 – Jul 16 |
| Carrots | Sow outdoors (spring) | May 13 – Jun 28 |
| Carrots | Sow outdoors (fall) | May 16 – Jul 1 |
| Garlic | Plant outdoors (fall) | Sep 15 – Oct 16 |
Where these dates come from
ZIP code 98943 is matched to the NOAA station Cle Elum, WA, 3.1 km away, at 1,900 ft elevation (26 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Cle Elum, WA (used) | 1,900 ft | May 13 | Sep 25 |
| Easton, WA | 2,170 ft | May 9 | Oct 6 |
| Stampede Pass, WA | 3,959 ft | May 14 | Oct 17 |
| Ellensburg Bowers Fld, WA | 1,766 ft | Apr 28 | Oct 7 |
Frost dates near South Cle Elum
- Cle Elum, WA 98922 · last May 13, first Sep 25
- Roslyn, WA 98941 · last May 9, first Oct 6
- Ronald, WA 98940 · last May 9, first Oct 6
- Easton, WA 98925 · last May 9, first Oct 6
- Thorp, WA 98946 · last Apr 28, first Oct 7
- Ellensburg, WA 98926 · last May 8, first Oct 2
- Naches, WA 98937 · last May 9, first Oct 6
- Snoqualmie Pass, WA 98068 · last May 14, first Oct 17
Frequently asked questions
- When is the last frost in South Cle Elum, WA?
- For ZIP code 98943, the average last spring frost (32°F) is May 13, based on NOAA 1991-2020 climate normals for the Cle Elum, WA weather station. There is a 1-in-10 chance of a frost after June 1.
- When is the first frost in South Cle Elum, WA?
- The average first fall frost (32°F) is September 25. There is a 1-in-10 chance of frost by September 11, so tender plants are at risk from that point on.
- How long is the growing season in 98943?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 132 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.