Last spring's pre-emergent window, largest Oregon cities
Each bar runs from the day the soil held 50°F to the day it held 55°F (2026).
- 50°F to 55°F
Every Oregon city
Spring 2026 dates and today's verdict.
| City | Held 50°F (2026) | Held 55°F (2026) | Soil today | Today |
|---|---|---|---|---|
| Portland, OR | Apr 6 | Apr 30 | 55°F | Season over |
| Eugene, OR | May 1 | May 5 | 54°F | Season over |
| Salem, OR | Apr 27 | May 4 | 55°F | Season over |
| Bend, OR | Apr 30 | May 2 | 50°F | Season over |
| Medford, OR | Mar 18 | May 4 | 52°F | Season over |
| Corvallis, OR | May 1 | May 5 | 55°F | Season over |
| Grants Pass, OR | Apr 28 | May 3 | 52°F | Season over |
| McMinnville, OR | Apr 29 | May 4 | 54°F | Season over |
| Redmond, OR | Apr 29 | May 2 | 51°F | Season over |
| Woodburn, OR | Apr 28 | May 4 | 54°F | Season over |
| Forest Grove, OR | Apr 6 | May 2 | 54°F | Season over |
| Roseburg, OR | May 2 | Jun 13 | 54°F | Season over |
| Klamath Falls, OR | Mar 19 | May 5 | 46°F | Season over |
| Hermiston, OR | Mar 16 | Apr 28 | 54°F | Season over |
| Pendleton, OR | Apr 30 | May 3 | 53°F | Season over |
| Lebanon, OR | May 2 | Jun 14 | 54°F | Season over |
| Coos Bay, OR | May 1 | Jun 14 | 56°F | Season over |
| The Dalles, OR | May 1 | May 4 | 48°F | Season over |
Crabgrass seeds start to germinate once the top 2 to 4 inches of soil stay near 55°F for several days. A pre-emergent works as a barrier in the soil, so it has to be down and watered in before that: the usual advice is to apply it while the soil holds 50 to 55°F. The dates here are when the modelled soil began to hold each temperature last spring; this year's window will move with the weather, which is why each city page shows today's reading and the 7-day forecast.
Questions
- When should I put down crabgrass preventer in Oregon?
- When the soil holds 50 to 55°F. Last spring that was around Apr 29 to May 4 across 18 Oregon cities, earlier in the south and in cities.
- Is it too late to apply pre-emergent?
- Once the soil has held 55°F for a week or more, crabgrass is germinating and a pre-emergent will not stop the seedlings already up. Each city page says which side of that line it is on today.
Soil temperature today in Oregon →
Data: Global Forecast System (GFS) 0.25°, soil temperature 0–10 cm (TSOIL) (NOAA National Centers for Environmental Prediction (NCEP)); GeoNames gazetteer (cities15000) (GeoNames).