The current average 2-inch soil temperature across Washington is 72°F. Readings range from 66°F to 82°F, from 5 USDA and NOAA monitoring stations. Soil across Washington is right at the seasonal normal of 72°F for mid-August, based on 5 of 5 stations with historical records. Washington spans USDA hardiness zones 6b to 9a, cool-season grass country. Last updated August 16, 2026.
Summer conditions across Washington with soil averaging 72°F at 2 inches. Warm-season grasses are in peak growth; keep cool-season lawns mowed high and watered deep. The next application windows arrive in fall, starting with pre-emergent as soil falls back through 70°F.
For cool-season lawns (fescue, bluegrass, ryegrass), fall is the best time to plant grass seed in Washington, with spring the second choice: fall seedlings face less weed competition and mature before summer heat. The window opens as 2-inch soil falls back through 70°F, and germination slows sharply once soil drops below 50°F, typically around October 22.
Spring is the second choice: the window opens when soil first holds 50°F and narrows as soil passes 65°F, typically by June 25.
| Region | Typical spring window opens | Typical fall window opens | Stations |
|---|---|---|---|
| Eastern Washington | May 2 | August 22 | 2 |
| Central Washington | April 18 | — | 3 |
Fall seeding also needs a stop date: new seedlings want about six weeks of growth before frost arrives. Your city page estimates the last safe seeding date from its nearest station: see when to plant in Seattle, when to plant in Tacoma or when to plant in Spokane. Readings current through August 16, 2026: Washington averages 72°F at 2 inches right now; the Current Planting Conditions section above reads that number against the season.
Typical dates are computed from historical 2-inch soil temperature averages at 5 monitoring stations in Washington; your own window depends on your nearest station's readings.
Historical 2-inch soil temperature normals for Washington: the median across 5 in-state stations with multi-year records. Any given year runs ahead of or behind these values; the live average at the top of this page shows where this year stands.
| Month | Average 2-inch soil temperature |
|---|---|
| January | 34°F |
| February | 35°F |
| March | 40°F |
| April | 47°F |
| May | 55°F |
| June | 63°F |
| July | 68°F |
| August | 67°F |
| September | 62°F |
| October | 51°F |
| November | 39°F |
| December | 35°F |
Grass seed germination
Grass seed germination temperatures across Washington. Soil warmth varies by location, so check a city page for the live reading and what germinates there now.
| Grass species | Seeding soil temp (2 in) | Days |
|---|---|---|
| Kentucky bluegrass | 50–65°F | 14-30 |
| Tall fescue | 50–65°F | 7-12 |
| Perennial ryegrass | 50–65°F | 5-10 |
| Fine fescue | 50–65°F | 7-14 |
| Bermudagrass | 75–90°F | 10-30 |
For root-zone timing (fertilizer, aeration, weed control), see the 4-inch soil temperature for Washington. For accumulated-heat timing, see growing degree days for Washington. For how wet the ground is versus normal, see soil moisture for Washington. See the Washington soil temperature map for the full station view.
Interpolated from the latest 4-inch readings and refreshed daily.
| Station | 2" Temp | Last Reading |
|---|---|---|
| Lind #1 (Adams) | 82°F | 2026-08-16 |
| Cook Farm Field D (Whitman) | 73°F | 2026-08-16 |
| Spokane 17 SSW | 72°F | 2026-08-16 |
| Darrington 21 NNE | 66°F | 2026-08-16 |
| Quinault 4 NE | 67°F | 2026-08-16 |
Current 2-inch readings grouped along Washington's east-to-west axis. Regional spread matters for timing: the warm end of the state can open an application window a week or more before the cool end.
| Region | Avg 2" Temp | Range | Stations |
|---|---|---|---|
| Eastern Washington (Whitman County) | 73°F | 72–73°F | 2 |
| Central Washington (Adams County) | 71°F | 66–82°F | 3 |
| City | ZIP | Current Temp |
|---|---|---|
| Auburn | 98001 | 67°F |
| Bellevue | 98004 | 66°F |
| Bellingham | 98225 | 66°F |
| Blaine | 98230 | 66°F |
| Bothell | 98011 | 66°F |
| Bremerton | 98310 | 67°F |
| Edmonds | 98020 | 66°F |
| Everett | 98201 | 66°F |
| Federal Way | 98003 | 67°F |
| Gig Harbor | 98329 | 67°F |
| Issaquah | 98027 | 61°F* |
| Kennewick | 99336 | 82°F |
| Kent | 98030 | 67°F* |
| Kirkland | 98033 | 66°F |
| Lacey | 98503 | 67°F |
| Lakewood | 98439 | 67°F |
| Lynnwood | 98036 | 66°F |
| Marysville | 98270 | 66°F |
| Mount Vernon | 98273 | 66°F |
| Oak Harbor | 98277 | 66°F |
| Olympia | 98501 | 67°F |
| Pasco | 99301 | 82°F |
| Port Angeles | 98362 | 67°F |
| Port Orchard | 98366 | 67°F |
| Pullman | 99163 | 73°F |
| Puyallup | 98371 | 67°F |
| Redmond | 98052 | 66°F |
| Renton | 98055 | 67°F |
| Richland | 99352 | 82°F |
| Sammamish | 98074 | 66°F |
| Seattle | 98101 | 67°F |
| Silverdale | 98315 | 67°F |
| Snohomish | 98290 | 66°F |
| Spokane | 99201 | 72°F |
| Sumner | 98352 | 65°F* |
| Tacoma | 98401 | 67°F |
| Vancouver | 98660 | 71°F* |
| Wenatchee | 98801 | 83°F* |
| Woodinville | 98072 | 66°F |
| Yakima | 98901 | 77°F* |
Modeled estimate where no monitoring station is within 75 miles; all other readings are measured at USDA and NOAA stations.
Fall is the best time to overseed a thin lawn.
Core aeration relieves compaction, but timing decides whether the lawn recovers in a week or struggles for a month.
Brown patch and Pythium strike when humid nights hold above 68°F on lush, over-fertilized turf; dollar spot, red thread, and rust hit slow-growing lawns at 60-85°F.
Check whether your soil is warm enough for the seed you bought: cool-season grass seeds into 50-65°F soil (tall fescue prefers 60°F and up), warm-season into 75-85°F.
The current average 2-inch soil temperature across Washington is 72°F. Readings range from 66°F to 82°F depending on location and elevation, from 5 USDA and NOAA monitoring stations. Soil across Washington is right at the seasonal normal of 72°F for mid-August, based on 5 of 5 stations with historical records.
Apply pre-emergent herbicide when soil at 2 inches reaches 55°F for several consecutive days. Timing varies across Washington, so check your city's page for station-specific readings and the pre-emergent timing recommendation.
Washington spans USDA hardiness zones 6b to 9a, cool-season grass country. For cool-season grasses (fescue, bluegrass), the fall window typically opens around August 22 and the spring window around April 25, based on historical 2-inch soil temperature averages at 5 in-state stations. Timing varies by location, so check your city's planting window for the dates specific to your area.