Seattle (Bitter Lake) (98133) — USDA Zone 8b

Frost dates and growing season for 98133

These are 50%-probability averages modeled from this ZIP's USDA hardiness zone and regional climate normals — not a single-station reading. In a typical year the last spring frost will have passed by March 24, but in a colder-than-average year it can run 1-2 weeks later. Plant tender crops (tomatoes, peppers, basil) once both soil and night temperatures are consistently warm — a thermometer beats the calendar.

Growing season in Seattle (Bitter Lake)

Seattle (Bitter Lake), Washington sits in USDA Zone 8b, with roughly 233 frost-free days between an average last spring frost around March 24 and a first fall frost around November 12. That is a long season — succession-sow through summer and run a full fall crop; heat-sensitive greens still need spring/autumn timing.

What grows in Seattle (Bitter Lake)

Seattle (Bitter Lake) falls in USDA Zone 8b, which means the same hardiness constraints apply as the full Zone 8 guide. Vegetables, herbs, and fruit trees rated to Zone 8b (or hardier) will overwinter here in a typical year.

• Tomatoes (spring + fall plantings)
• Peppers (sweet + hot)
• Okra
• Sweet potatoes
• Southern peas
• Melons, watermelon
• Figs
• Pomegranates
• Citrus (in protected spots — Meyer lemon)
• Pecans

What to plant in Seattle (Bitter Lake) this week

Seattle (Bitter Lake) is in high summer — most spring plantings are in. Keep an eye on watering and start planning your fall crop. Cool-season seedlings (broccoli, cabbage, lettuce) can be started indoors for a fall transplant.

• When to plant tomatoes in zone 8
• When to plant peppers in zone 8
• When to plant bush beans in zone 8
• When to plant cucumbers in zone 8
• When to plant basil in zone 8

Full planting calendar for Seattle (Bitter Lake)

Crop-by-crop sowing, transplant, and harvest dates calibrated to zone 8 averages:

• When to plant tomatoes in zone 8
• When to plant peppers in zone 8
• When to plant basil in zone 8
• When to plant garlic in zone 8
• When to plant lettuce in zone 8
• When to plant bush beans in zone 8
• When to plant cucumbers in zone 8
• When to plant summer squash in zone 8
• When to plant peas in zone 8
• When to plant carrots in zone 8
• When to plant broccoli in zone 8
• When to plant cauliflower in zone 8
• When to plant cabbage in zone 8
• When to plant kale in zone 8
• When to plant brussels sprouts in zone 8
• When to plant collard greens in zone 8
• When to plant spinach in zone 8
• When to plant swiss chard in zone 8
• When to plant arugula in zone 8
• When to plant beets in zone 8
• When to plant radishes in zone 8
• When to plant turnips in zone 8
• When to plant parsnips in zone 8
• When to plant kohlrabi in zone 8
• When to plant onions in zone 8
• When to plant leeks in zone 8
• When to plant celery in zone 8
• When to plant asparagus in zone 8
• When to plant rhubarb in zone 8
• When to plant potatoes in zone 8
• When to plant sweet potatoes in zone 8
• When to plant eggplant in zone 8
• When to plant okra in zone 8
• When to plant sweet corn in zone 8
• When to plant pumpkins in zone 8
• When to plant winter squash in zone 8
• When to plant zucchini in zone 8
• When to plant cantaloupe in zone 8
• When to plant watermelon in zone 8
• When to plant pole beans in zone 8
• When to plant edamame in zone 8
• When to plant fava beans in zone 8
• When to plant cilantro in zone 8
• When to plant dill in zone 8
• When to plant parsley in zone 8
• When to plant oregano in zone 8
• When to plant thyme in zone 8
• When to plant sage in zone 8
• When to plant rosemary in zone 8
• When to plant chives in zone 8

Local microclimate notes

Zone tables give you the average — but Seattle (Bitter Lake)gardens vary. South-facing walls and paved areas can run a full half-zone warmer than the published rating. Low-lying spots, frost pockets, and shaded north sides can run colder. If you've gardened here a few seasons, your own frost record (the last time you actually got frost damage) is more accurate than any national average.

Source and methodology

Hardiness zone from the USDA Plant Hardiness Zone Map (2023 revision). Frost-date and growing-season figures are modeled from this ZIP's USDA hardiness zone and regional NOAA 1991-2020 climate normals — they are zone-level estimates, not a per-station record, so treat them as planning guidance and confirm against your own local frost history. Crop recommendations are drawn from US Cooperative Extension references and curated by the Growli editorial team. Last reviewed May 2026.

Nearby ZIP codes in Washington

• 98101 — Seattle (Zone 9a)
• 98109 — Seattle (Queen Anne) (Zone 9a)
• 98103 — Seattle (Fremont) (Zone 8b)
• 98501 — Olympia (Zone 8b)
• 98401 — Tacoma (Zone 8b)
• 98201 — Everett (Zone 8b)
• 98225 — Bellingham (Zone 8b)
• 99201 — Spokane (Zone 7a)
• 98660 — Vancouver (Zone 8b)
• 98801 — Wenatchee (Zone 6b)
• 98105 — Seattle (University District) (Zone 9a)
• 98115 — Seattle (Wedgwood) (Zone 9a)
• Browse all US ZIP codes by state

Related guides

• USDA hardiness zone for Seattle, WA
• USDA Zone 8 — full plant + frost guide
• Look up another ZIP code
• Watering frequency calculator
• How to start a vegetable garden — beginner guide