Frost dates for 98006Bellevue, WA
The average last spring frost in Bellevue is April 20 and the average first fall frost is October 25, giving a typical growing season of about 187 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 20
- Average first fall frost
- Oct 25
- Growing season
- 187 days
Safer after May 10 (1-in-10 risk)
Possible by Oct 5 (1-in-10 risk)
Last frost typically in 170 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 23 · May 10 · Jun 7 | Sep 19 · Oct 6 · Oct 26 | 146 days | 100% |
| Frost / freeze (32°F) | Mar 31 · Apr 20 · May 10 | Oct 5 · Oct 25 · Nov 12 | 187 days | 100% |
| Hard freeze (28°F) | Feb 28 · Mar 24 · Apr 16 | Oct 24 · Nov 12 · Dec 8 | 233 days | 100% |
Planting calendar for Bellevue
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 20 – May 26 |
| Tomatoes | Transplant outdoors | May 6 – Jul 5 |
| Peppers | Start seeds indoors | Mar 20 – Apr 20 |
| Peppers | Transplant outdoors | May 20 – Jun 20 |
| Eggplant | Start seeds indoors | Apr 6 – May 5 |
| Eggplant | Transplant outdoors | May 20 – Jun 20 |
| Cucumbers | Sow outdoors | May 20 – Jul 15 |
| Summer squash | Sow outdoors | May 6 – Jun 20 |
| Winter squash & pumpkins | Sow outdoors | May 20 – Jun 20 |
| Snap beans | Sow outdoors | May 6 – Aug 7 |
| Sweet corn | Sow outdoors | May 6 – Jul 5 |
| Watermelon & cantaloupe | Sow outdoors | May 20 – Jun 20 |
| Okra | Sow outdoors | May 13 – Jun 5 |
| Peas | Sow outdoors (spring) | Mar 20 – May 5 |
| Potatoes | Plant outdoors (spring) | Mar 20 – May 20 |
| Onions | Start seeds indoors (spring) | Feb 6 – Mar 5 |
| Onions | Transplant outdoors (spring) | Apr 6 – May 5 |
| Broccoli | Start seeds indoors (spring) | Mar 2 – Apr 5 |
| Broccoli | Transplant outdoors (spring) | Apr 6 – May 5 |
| Broccoli | Start seeds indoors (fall) | Jun 25 – Jul 5 |
| Broccoli | Transplant outdoors (fall) | Jul 25 – Aug 5 |
| Cabbage | Start seeds indoors (spring) | Feb 20 – Mar 20 |
| Cabbage | Transplant outdoors (spring) | Mar 20 – Apr 20 |
| Cabbage | Start seeds indoors (fall) | Jun 15 – Jul 15 |
| Cabbage | Transplant outdoors (fall) | Jul 15 – Aug 15 |
| Leaf lettuce | Sow outdoors (spring) | Mar 20 – Jun 5 |
| Leaf lettuce | Sow outdoors (fall) | Jul 15 – Aug 31 |
| Spinach | Sow outdoors (spring) | Mar 13 – Apr 26 |
| Spinach | Sow outdoors (fall) | Aug 1 – Sep 5 |
| Radishes | Sow outdoors (spring) | Mar 20 – May 10 |
| Radishes | Sow outdoors (fall) | Jul 15 – Sep 15 |
| Kale | Sow outdoors (spring) | Apr 6 – Apr 26 |
| Kale | Sow outdoors (fall) | Jul 8 – Aug 15 |
| Carrots | Sow outdoors (spring) | Apr 20 – Jun 5 |
| Carrots | Sow outdoors (fall) | Jun 15 – Jul 31 |
| Garlic | Plant outdoors (fall) | Oct 15 – Nov 15 |
Where these dates come from
ZIP code 98006 is matched to the NOAA station Landsburg, WA, 25.2 km away, at 535 ft elevation (282 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Landsburg, WA (used) | 535 ft | Apr 20 | Oct 25 |
| Renton Muni Ap, WA | 29 ft | Mar 13 | Nov 16 |
| Seattle Boeing Fld, WA | 20 ft | Mar 13 | Nov 17 |
| Seattle Sand Pt Wsfo, WA | 60 ft | Mar 8 | Nov 23 |
Frost dates near Bellevue
- Mercer Island, WA 98040 · last Mar 13, first Nov 17
- Bellevue, WA 98005 · last Mar 8, first Nov 23
- Renton, WA 98056 · last Mar 2, first Nov 23
- Medina, WA 98039 · last Mar 8, first Nov 23
- Seattle, WA 98118 · last Mar 13, first Nov 17
- Sammamish, WA 98075 · last Mar 30, first Nov 7
- Issaquah, WA 98029 · last Mar 30, first Nov 7
- Redmond, WA 98052 · last Mar 8, first Nov 23
Frequently asked questions
- When is the last frost in Bellevue, WA?
- For ZIP code 98006, the average last spring frost (32°F) is April 20, based on NOAA 1991-2020 climate normals for the Landsburg, WA weather station. There is a 1-in-10 chance of a frost after May 10.
- When is the first frost in Bellevue, WA?
- The average first fall frost (32°F) is October 25. There is a 1-in-10 chance of frost by October 5, so tender plants are at risk from that point on.
- How long is the growing season in 98006?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 187 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.