Growing Degree Days in Washington
Washington has accumulated about 543 GDD so far this year (base 50°F, since January 1), averaged across 3 NOAA USCRN stations. Station totals range from 395 to 642 GDD. Through July 1, 2026.
How to Read This Number
Growing degree days count accumulated heat: each day adds the amount its average temperature runs above 50°F, the point where cool-season growth and most pests get going. Turf managers use the running total to time crabgrass pre-emergent, annual bluegrass seedhead suppression, plant growth regulator reapplication, and grub control. Treat it as a timing signal read against a model, not a fixed date. The total here is measured air temperature from NOAA USCRN stations, base 50°F, accumulated from January 1 — state the model whenever you compare totals, because a different base or start date is not interchangeable.
USCRN Stations in Washington (3)
| Station | GDD (base 50°F) | Through |
|---|---|---|
| Darrington 21 NNE | 642 | 2026-07-01 |
| Quinault 4 NE | 592 | 2026-07-01 |
| Spokane 17 SSW | 395 | 2026-07-01 |
Cities in Washington (40)
Each city page pairs its local growing-degree-day total with the current soil temperature from the nearest monitoring station.
- Auburn
- Bellevue
- Bellingham
- Blaine
- Bothell
- Bremerton
- Edmonds
- Everett
- Federal Way
- Gig Harbor
- Issaquah
- Kennewick
- Kent
- Kirkland
- Lacey
- Lakewood
- Lynnwood
- Marysville
- Mount Vernon
- Oak Harbor
- Olympia
- Pasco
- Port Angeles
- Port Orchard
- Pullman
- Puyallup
- Redmond
- Renton
- Richland
- Sammamish
- Seattle
- Silverdale
- Snohomish
- Spokane
- Sumner
- Tacoma
- Vancouver
- Wenatchee
- Woodinville
- Yakima
Growing Degree Days FAQ for Washington
How many growing degree days has Washington accumulated this year?
Washington has accumulated about 543 growing degree days (base 50°F, since January 1), averaged across 3 NOAA USCRN stations. Station totals range from 395 to 642 GDD. The total climbs through summer and levels off as temperatures fall.
What base temperature and start date are these totals?
These are base 50°F growing degree days accumulated from January 1, the turf-industry convention. Each day adds the amount its average air temperature runs above 50°F, floored at zero. Totals from a different base or start date are not interchangeable, so the model is stated explicitly wherever a number appears.
What are growing degree days used for in lawn care?
Turf managers track the running total to time temperature-driven tasks: crabgrass pre-emergent before germination, annual bluegrass seedhead suppression, plant growth regulator reapplication, and grub control. Growing degree days are a timing signal read against a model, not a fixed calendar date.
See growing degree days for every state, read the growing degree days lawn-care guide, or browse the full Washington soil temperature directory.