4-Inch Soil Temperature in Washington
The current average 4-inch soil temperature across Washington is 61°F, measured at 5 USDA and NOAA monitoring stations. Readings range from 56°F to 66°F. Soil across Washington is right at the seasonal normal of 60°F for late September, based on 5 of 5 stations with historical records. Last updated September 23, 2026.
Why the 4-Inch Reading
Every reading here is measured at native 4-inch depth by USDA SCAN (Soil Climate Analysis Network) and NOAA USCRN (US Climate Reference Network) stations, not modeled. The 4-inch root-zone temperature changes more slowly than the surface, making it the steadier signal for established-lawn and garden timing: pre-emergent and broadleaf herbicide windows, fertilizer applications, and core aeration.
Stations Measuring 4-Inch Depth in Washington (5)
| Station | 4" Temp | Last Reading |
|---|---|---|
| Lind #1 (Adams) | 66°F | 2026-09-23 |
| Cook Farm Field D (Whitman) | 62°F | 2026-09-23 |
| Spokane 17 SSW | 59°F | 2026-09-23 |
| Darrington 21 NNE | 56°F | 2026-09-23 |
| Quinault 4 NE | 60°F | 2026-09-23 |
Cities in Washington (40)
| City | ZIP | Current Temp |
|---|---|---|
| Auburn | 98001 | 60°F |
| Bellevue | 98004 | 56°F |
| Bellingham | 98225 | 56°F |
| Blaine | 98230 | 56°F |
| Bothell | 98011 | 56°F |
| Bremerton | 98310 | 60°F |
| Edmonds | 98020 | 56°F |
| Everett | 98201 | 56°F |
| Federal Way | 98003 | 60°F |
| Gig Harbor | 98329 | 60°F |
| Issaquah | 98027 | 56°F |
| Kennewick | 99336 | 66°F |
| Kent | 98030 | 60°F |
| Kirkland | 98033 | 56°F |
| Lacey | 98503 | 60°F |
| Lakewood | 98439 | 60°F |
| Lynnwood | 98036 | 56°F |
| Marysville | 98270 | 56°F |
| Mount Vernon | 98273 | 56°F |
| Oak Harbor | 98277 | 56°F |
| Olympia | 98501 | 60°F |
| Pasco | 99301 | 66°F |
| Port Angeles | 98362 | 60°F |
| Port Orchard | 98366 | 60°F |
| Pullman | 99163 | 62°F |
| Puyallup | 98371 | 60°F |
| Redmond | 98052 | 56°F |
| Renton | 98055 | 60°F |
| Richland | 99352 | 66°F |
| Sammamish | 98074 | 56°F |
| Seattle | 98101 | 60°F |
| Silverdale | 98315 | 60°F |
| Snohomish | 98290 | 56°F |
| Spokane | 99201 | 59°F |
| Sumner | 98352 | 60°F |
| Tacoma | 98401 | 60°F |
| Vancouver | 98660 | — |
| Wenatchee | 98801 | 66°F |
| Woodinville | 98072 | 56°F |
| Yakima | 98901 | 66°F |
4-Inch Soil Temperature FAQ for Washington
What is the current 4-inch soil temperature in Washington?
The current average 4-inch soil temperature across Washington is 61°F, measured at 5 USDA and NOAA stations. Readings range from 56°F to 66°F depending on location and elevation. Soil across Washington is right at the seasonal normal of 60°F for late September, based on 5 of 5 stations with historical records.
What does the 4 inch soil temperature mean?
The 4 inch soil temperature shows conditions deeper in the root zone than the 2 inch germination reading. It is commonly used for established lawn, garden, and agricultural timing because it changes more slowly than the surface layer, so it is a steadier signal for fertilizer, aeration, and weed-control decisions.
Why use 4-inch soil temperature instead of 2-inch?
Use 2 inches for germination decisions, since that is where seeds sit. Use the 4 inch soil temperature for established lawn and garden timing: it reads the root zone, changes more slowly than the surface, and is the depth most fertilizer, aeration, and disease guidance references.
See the national 4-inch soil temperature map, the full Washington soil temperature directory (all depths), the national soil temperature by depth comparison, or the live national soil temperature map.