Frost dates for 98008Bellevue, WA
The average last spring frost in Bellevue is March 8 and the average first fall frost is November 23, giving a typical growing season of about 259 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Mar 8
- Average first fall frost
- Nov 23
- Growing season
- 259 days
Safer after Mar 29 (1-in-10 risk)
Possible by Nov 4 (1-in-10 risk)
First frost typically in 21 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) | Mar 17 · Apr 4 · Apr 26 | Oct 24 · Nov 5 · Nov 22 | 215 days | 100% |
| Frost / freeze (32°F) | Feb 13 · Mar 8 · Mar 29 | Nov 4 · Nov 23 · Dec 16 | 259 days | 100% |
| Hard freeze (28°F) | Dec 27 · Feb 11 · Mar 1 | Nov 17 · Dec 11 · Jan 17 | 308 days | 96% |
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 | Feb 5 – Apr 13 |
| Tomatoes | Transplant outdoors | Mar 24 – Aug 3 |
| Peppers | Start seeds indoors | Feb 5 – Mar 8 |
| Peppers | Transplant outdoors | Apr 7 – May 8 |
| Eggplant | Start seeds indoors | Feb 22 – Mar 23 |
| Eggplant | Transplant outdoors | Apr 7 – May 8 |
| Cucumbers | Sow outdoors | Apr 7 – Aug 13 |
| Summer squash | Sow outdoors | Mar 24 – May 8 |
| Winter squash & pumpkins | Sow outdoors | Apr 7 – May 8 |
| Snap beans | Sow outdoors | Mar 24 – Sep 5 |
| Sweet corn | Sow outdoors | Mar 24 – Aug 3 |
| Watermelon & cantaloupe | Sow outdoors | Apr 7 – May 8 |
| Okra | Sow outdoors | Mar 31 – Apr 23 |
| Peas | Sow outdoors (spring) | Feb 5 – Mar 23 |
| Potatoes | Plant outdoors (spring) | Feb 5 – Apr 7 |
| Onions | Start seeds indoors (spring) | Dec 25 – Jan 21 |
| Onions | Transplant outdoors (spring) | Feb 22 – Mar 23 |
| Broccoli | Start seeds indoors (spring) | Jan 18 – Feb 21 |
| Broccoli | Transplant outdoors (spring) | Feb 22 – Mar 23 |
| Broccoli | Start seeds indoors (fall) | Jul 24 – Aug 3 |
| Broccoli | Transplant outdoors (fall) | Aug 23 – Sep 3 |
| Cabbage | Start seeds indoors (spring) | Jan 8 – Feb 5 |
| Cabbage | Transplant outdoors (spring) | Feb 5 – Mar 8 |
| Cabbage | Start seeds indoors (fall) | Jul 14 – Aug 13 |
| Cabbage | Transplant outdoors (fall) | Aug 13 – Sep 13 |
| Leaf lettuce | Sow outdoors (spring) | Feb 5 – Apr 23 |
| Leaf lettuce | Sow outdoors (fall) | Aug 13 – Sep 29 |
| Spinach | Sow outdoors (spring) | Jan 29 – Mar 14 |
| Spinach | Sow outdoors (fall) | Aug 30 – Oct 4 |
| Radishes | Sow outdoors (spring) | Feb 5 – Mar 28 |
| Radishes | Sow outdoors (fall) | Aug 13 – Oct 14 |
| Kale | Sow outdoors (spring) | Feb 22 – Mar 14 |
| Kale | Sow outdoors (fall) | Aug 6 – Sep 13 |
| Carrots | Sow outdoors (spring) | Mar 8 – Apr 23 |
| Carrots | Sow outdoors (fall) | Jul 14 – Aug 29 |
| Garlic | Plant outdoors (fall) | Nov 13 – Dec 14 |
Where these dates come from
ZIP code 98008 is matched to the NOAA station Seattle Sand Pt Wsfo, WA, 13.4 km away, at 60 ft elevation (196 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Seattle Sand Pt Wsfo, WA (used) | 60 ft | Mar 8 | Nov 23 |
| Renton Muni Ap, WA | 29 ft | Mar 13 | Nov 16 |
| Seattle Boeing Fld, WA | 20 ft | Mar 13 | Nov 17 |
| Snoqualmie Falls, WA | 440 ft | Mar 30 | Nov 7 |
Frost dates near Bellevue
- Bellevue, WA 98007 · last Mar 8, first Nov 23
- Sammamish, WA 98074 · last Mar 30, first Nov 7
- Redmond, WA 98052 · last Mar 8, first Nov 23
- Medina, WA 98039 · last Mar 8, first Nov 23
- Kirkland, WA 98033 · last Mar 8, first Nov 23
- Mercer Island, WA 98040 · last Mar 13, first Nov 17
- Issaquah, WA 98029 · last Mar 30, first Nov 7
- Renton, WA 98059 · last Apr 20, first Oct 25
Frequently asked questions
- When is the last frost in Bellevue, WA?
- For ZIP code 98008, the average last spring frost (32°F) is March 8, based on NOAA 1991-2020 climate normals for the Seattle Sand Pt Wsfo, WA weather station. There is a 1-in-10 chance of a frost after March 29.
- When is the first frost in Bellevue, WA?
- The average first fall frost (32°F) is November 23. There is a 1-in-10 chance of frost by November 4, so tender plants are at risk from that point on.
- How long is the growing season in 98008?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 259 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.