What to do in Seattle now
Seattle is in the transition zone, where both cool- and warm-season lawns grow. Dates are typical for this spot, worked out from 23 years of weather at Seattle Boeing Field; each status uses this year's soil estimates.
Cool-season: tall fescue, Kentucky bluegrass, perennial ryegrass, fine fescue
- Crabgrass pre-emergent Closed Apr 24 Typical: Apr 7 – May 12-inch soil held 55°F for a week from Apr 24, so crabgrass was sprouting. Next window: about Apr 7 – May 1, 2027.
- Seed or overseed Late · risky Typical: Aug 29 – Oct 23Soil fell below 55°F on Oct 26. Seed sown now germinates slowly and may not survive winter. The hard stop, 4-inch soil under 50°F, typically comes around Nov 12.
- Late-fall feeding Final feeding from about Nov 12 Typical: Nov 12 – Dec 8Not too late. Feed on your normal fall schedule; the last feeding of the year goes down when 4-inch soil falls to about 50°F (typically Nov 12) and before it reaches 40°F (typically Dec 8).
Warm-season: bermudagrass, zoysia, St. Augustine, centipede, bahia
- Crabgrass pre-emergent Closed Apr 24 Typical: Apr 7 – May 12-inch soil held 55°F for a week from Apr 24, so crabgrass was sprouting. Next window: about Apr 7 – May 1, 2027.
- Seed or sod Wait for late spring Typical: Jun 5 – Aug 29Warm-season seed needs 4-inch soil at 65°F or more, and seedlings need the rest of summer to establish. Next window opens about Jun 5.
- Fall pre-emergent (Poa annua) Germinating since Sep 1 Typical: By Aug 264-inch soil fell below 70°F on Sep 1, when annual bluegrass begins to sprout. A pre-emergent now only stops later flushes; plan to apply by about Aug 26 next year.
- Dormancy and last feeding Dormant since about Oct 26 Typical: Around Oct 234-inch soil has stayed under 55°F since Oct 26, so warm-season grass is going brown. It is too late to fertilize; feed again after spring green-up, once soil holds 65°F (typically Jun 5).
The last 60 days and the week ahead
Seattle soil is 4° cooler than normal for Nov 3, cooler than on 84% of those dates since 2005, and 4° cooler than a year ago.
The green line is our estimate of the daily average soil temperature 2 inches down, driven by temperatures at Seattle Boeing Field, 8.7 km from the city center. The dashed part runs the National Weather Service forecast through the same model. Hover or tap for any day.
2-inch soil, estimated From the NWS forecast Normal Normal range (8 years in 10)
Show the numbers
| Date | 2-inch soil | 4-inch soil | Air high / low | Normal (2 in) |
|---|---|---|---|---|
| Oct 20 | 55° | 57° | 63° / 46° | 55° |
| Oct 21 | 55° | 56° | 64° / 43° | 54° |
| Oct 22 | 54° | 56° | 61° / 43° | 54° |
| Oct 23 | 52° | 55° | 58° / 41° | 53° |
| Oct 24 | 51° | 53° | 55° / 37° | 53° |
| Oct 25 | 51° | 53° | 58° / 48° | 52° |
| Oct 26 | 52° | 54° | 59° / 48° | 52° |
| Oct 27 | 52° | 54° | 58° / 48° | 51° |
| Oct 28 | 51° | 53° | 55° / 44° | 51° |
| Oct 29 | 51° | 53° | 56° / 43° | 51° |
| Oct 30 | 49° | 51° | 50° / 40° | 51° |
| Oct 31 | 48° | 50° | 53° / 36° | 50° |
| Nov 1 | 46° | 49° | 50° / 37° | 50° |
| Nov 2 | 45° | 48° | 52° / 34° | 50° |
| Nov 3 | 46° | 48° | 57° / 41° | 50° |
| Nov 4 (forecast) | 48° | 50° | 57° / 49° | 50° |
| Nov 5 (forecast) | 49° | 50° | 57° / 48° | 50° |
| Nov 6 (forecast) | 50° | 51° | 55° / 49° | 50° |
| Nov 7 (forecast) | 52° | 52° | 61° / 52° | 49° |
| Nov 8 (forecast) | 52° | 52° | 56° / 46° | 49° |
| Nov 9 (forecast) | 52° | 52° | 55° / 49° | 49° |
Which grass grows in Seattle
With January averaging 43°F, Seattle sits in the transition zone. Tall fescue is the common cool-season choice; bermudagrass and zoysia are the common warm-season ones. Use the switch above to see the calendar for yours.
Seattle soil through the year
Weekly 2-inch estimates for 2026 so far against 2025 and the normal for each week. The red lines mark 50°F, when crabgrass pre-emergent should be down, and 65°F, when warm-season seed sprouts well.
2026 2025 Normal (2005–2025) 8 years in 10
Normal by month
| Month | 2 in | 4 in | Air |
|---|---|---|---|
| Jan | 41° | 42° | 43° |
| Feb | 42° | 44° | 44° |
| Mar | 46° | 47° | 47° |
| Apr | 51° | 52° | 52° |
| May | 59° | 60° | 58° |
| Jun | 64° | 65° | 63° |
| Jul | 70° | 71° | 67° |
| Aug | 70° | 72° | 68° |
| Sep | 65° | 67° | 63° |
| Oct | 55° | 57° | 54° |
| Nov | 47° | 48° | 46° |
| Dec | 41° | 43° | 42° |
Soil: average of our daily estimates, 2005–2025. Air: NOAA 1991–2020 normals for the station.
Typical lawn dates in Seattle
Each date is when the soil estimate (or the air, for freezes) crossed the threshold, year by year since 2005. “Early” and “late” are the 10th and 90th percentile years, so 8 years in 10 fall between them.
| Event | Typical | 2026 |
|---|---|---|
| Last spring freeze (32°F) | Mar 11 | Mar 30 |
| Crabgrass model: 250 growing degree days | Jan 25 | Jan 20 |
| Pre-emergent window opens (2-inch soil 50°F) | Apr 7 | Apr 7 |
| Crabgrass begins to sprout (2-inch soil 55°F) | May 1 | Apr 24 |
| Cool-season lawns start growing (4-inch soil 55°F) | Apr 26 | Apr 23 |
| Warm-season seeding opens (4-inch soil 65°F) | Jun 5 | Jun 15 |
| Cool-season seeding opens (4-inch soil under 70°F) | Aug 29 | Sep 2 |
| Cool-season seeding ends (4-inch soil under 55°F) | Oct 23 | Oct 26 |
| Warm-season grass goes dormant (4-inch under 55°F) | Oct 23 | Oct 26 |
| First fall freeze (32°F) | Nov 14 | not yet |
| Roots stop feeding (4-inch soil under 40°F) (in 13 of 21 years) | Dec 8 | not yet |
Where these numbers come from
There is no soil sensor in most cities, so we estimate it. Shallow soil follows air temperature with a lag of a few days, and runs a little warmer than the air in fall. We fitted that relationship to 190 USDA soil-sensor stations; on years held out of the fit, the estimate was off by 3.3°F on an average day, and it put the spring 55°F date within a median of 3 days. Read the methodology.
Weather: RCC ACIS station KBFI (SEATTLE BOEING FIELD), daily data since 1948. Forecast: National Weather Service, SEW office, issued Nov 4, 2026, 1:26 AM EST. Last observed day: Nov 3, 2026.
Seattle questions
What is the soil temperature in Seattle today? Our estimate for Nov 3 is 46°F at 2 inches and 48°F at 4 inches, as a daily average. Early-morning soil runs a few degrees cooler than that, and afternoon soil warmer.
When should I put down crabgrass pre-emergent in Seattle? Apply when 2-inch soil holds about 50°F and before it holds 55°F. That has typically been Apr 7 to May 1 in Seattle. For 2026 the window closed on Apr 24.
When can I seed bermudagrass in Seattle? Wait for late spring. Warm-season seed needs 4-inch soil at 65°F or more, and seedlings need the rest of summer to establish. Next window opens about Jun 5.
Is it too late to fertilize in Seattle? Dormant since about Oct 26. 4-inch soil has stayed under 55°F since Oct 26, so warm-season grass is going brown. It is too late to fertilize; feed again after spring green-up, once soil holds 65°F (typically Jun 5).
When is the last frost in Seattle? The last 32°F night of spring has typically come around Mar 11, and as late as Apr 4 in 1 year in 10. The first fall freeze typically arrives around Nov 14.
Why 2 inches and 4 inches? Crabgrass and most weed seeds sprout in the top inch or two, so pre-emergent timing follows 2-inch soil. Grass seed and roots respond to the slightly steadier soil at about 4 inches.
How accurate is this? It is a model, not a probe in your yard. Expect about 3–4°F of difference on a given day; shade, slope, mulch and irrigation all move real soil. The dates and trends are more reliable than any single day.