What to do in Portland now
Portland 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 Portland Intl Airport; each status uses this year's soil estimates.
Cool-season: tall fescue, Kentucky bluegrass, perennial ryegrass, fine fescue
- Crabgrass pre-emergent Closed Apr 10 Typical: Apr 1 – Apr 232-inch soil held 55°F for a week from Apr 10, so crabgrass was sprouting. Next window: about Apr 1 – Apr 23, 2027.
- Seed or overseed Late · risky Typical: Sep 16 – Oct 29Soil fell below 55°F on Oct 29. Seed sown now germinates slowly and may not survive winter. The hard stop, 4-inch soil under 50°F, typically comes around Nov 14.
- Late-fall feeding Final feeding from about Nov 14 Typical: Nov 14 – 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 14) and before it reaches 40°F (typically Dec 8).
Warm-season: bermudagrass, zoysia, St. Augustine, centipede, bahia
- Crabgrass pre-emergent Closed Apr 10 Typical: Apr 1 – Apr 232-inch soil held 55°F for a week from Apr 10, so crabgrass was sprouting. Next window: about Apr 1 – Apr 23, 2027.
- Seed or sod Wait for late spring Typical: May 30 – Sep 16Warm-season seed needs 4-inch soil at 65°F or more, and seedlings need the rest of summer to establish. Next window opens about May 30.
- Fall pre-emergent (Poa annua) Germinating since Sep 4 Typical: By Sep 134-inch soil fell below 70°F on Sep 4, when annual bluegrass begins to sprout. A pre-emergent now only stops later flushes; plan to apply by about Sep 13 next year.
- Dormancy and last feeding Dormant since about Oct 29 Typical: Around Oct 294-inch soil has stayed under 55°F since Oct 29, 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 May 30).
The last 60 days and the week ahead
Portland soil is 2° cooler than normal for Nov 3, cooler than on 68% of those dates since 2005, and 1° cooler than a year ago.
The green line is our estimate of the daily average soil temperature 2 inches down, driven by temperatures at Portland Intl Airport, 7.3 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 | 59° | 60° | 75° / 47° | 57° |
| Oct 21 | 58° | 60° | 73° / 42° | 56° |
| Oct 22 | 57° | 59° | 65° / 44° | 56° |
| Oct 23 | 55° | 58° | 61° / 41° | 55° |
| Oct 24 | 53° | 55° | 57° / 36° | 55° |
| Oct 25 | 52° | 54° | 52° / 47° | 54° |
| Oct 26 | 52° | 54° | 56° / 51° | 54° |
| Oct 27 | 53° | 55° | 58° / 50° | 53° |
| Oct 28 | 53° | 54° | 57° / 48° | 53° |
| Oct 29 | 52° | 54° | 55° / 47° | 52° |
| Oct 30 | 52° | 54° | 58° / 45° | 52° |
| Oct 31 | 51° | 53° | 58° / 39° | 52° |
| Nov 1 | 48° | 51° | 47° / 39° | 52° |
| Nov 2 | 49° | 51° | 56° / 44° | 52° |
| Nov 3 | 50° | 52° | 59° / 47° | 52° |
| Nov 4 (forecast) | 51° | 52° | 58° / 48° | 52° |
| Nov 5 (forecast) | 51° | 52° | 59° / 45° | 51° |
| Nov 6 (forecast) | 51° | 53° | 58° / 47° | 51° |
| Nov 7 (forecast) | 53° | 54° | 63° / 50° | 51° |
| Nov 8 (forecast) | 52° | 53° | 57° / 45° | 50° |
| Nov 9 (forecast) | 52° | 53° | 57° / 47° | 50° |
Which grass grows in Portland
With January averaging 42°F, Portland 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.
Portland 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° | 42° |
| Feb | 43° | 44° | 44° |
| Mar | 47° | 48° | 48° |
| Apr | 53° | 54° | 53° |
| May | 60° | 62° | 59° |
| Jun | 66° | 67° | 64° |
| Jul | 72° | 74° | 70° |
| Aug | 73° | 75° | 71° |
| Sep | 67° | 69° | 65° |
| Oct | 57° | 59° | 56° |
| Nov | 47° | 49° | 47° |
| Dec | 41° | 42° | 42° |
Soil: average of our daily estimates, 2005–2025. Air: NOAA 1991–2020 normals for the station.
Typical lawn dates in Portland
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 18 | Mar 26 |
| Crabgrass model: 250 growing degree days | Jan 26 | Jan 28 |
| Pre-emergent window opens (2-inch soil 50°F) | Apr 1 | Mar 19 |
| Crabgrass begins to sprout (2-inch soil 55°F) | Apr 23 | Apr 10 |
| Cool-season lawns start growing (4-inch soil 55°F) | Apr 18 | Apr 9 |
| Warm-season seeding opens (4-inch soil 65°F) | May 30 | May 28 |
| Cool-season seeding opens (4-inch soil under 70°F) | Sep 16 | Sep 5 |
| Cool-season seeding ends (4-inch soil under 55°F) | Oct 29 | Oct 29 |
| Warm-season grass goes dormant (4-inch under 55°F) | Oct 29 | Oct 29 |
| First fall freeze (32°F) | Nov 20 | 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 KPDX (PORTLAND INTL AIRPORT), daily data since 1938. Forecast: National Weather Service, PQR office, issued Nov 4, 2026, 6:41 AM EST. Last observed day: Nov 3, 2026.
Portland questions
What is the soil temperature in Portland today? Our estimate for Nov 3 is 50°F at 2 inches and 52°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 Portland? Apply when 2-inch soil holds about 50°F and before it holds 55°F. That has typically been Apr 1 to Apr 23 in Portland. For 2026 the window closed on Apr 10.
When can I seed bermudagrass in Portland? 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 May 30.
Is it too late to fertilize in Portland? Dormant since about Oct 29. 4-inch soil has stayed under 55°F since Oct 29, 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 May 30).
When is the last frost in Portland? The last 32°F night of spring has typically come around Mar 18, and as late as Apr 8 in 1 year in 10. The first fall freeze typically arrives around Nov 20.
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.