Chehalis River near Grand Mound, WA
Southwest Washington · USGS gauge 12027500 · Updated Oct 24, 2:37 PM PDT · USGS data, provisional
Reading time: Oct 24, 2:00 PM PDT · Provisional data
Flow is in a typical range for the date. Rivers are generally easiest to fish and float when they are near their normal flow, but this status says nothing about water clarity, hatches, hazards such as wood in the river, or dam releases.
- Vs. normal for this date
- 11th percentile
- Typical range (25th–75th)
- 332–1,400 cfs
- Median for this date
- 660 cfs
- 7-day low / high
- 231 / 256 cfs
Plain-language explanation
Chehalis River near Grand Mound is flowing at 243 cubic feet per second (cfs) as of Oct 24, 2:00 PM PDT. That is on the low side for this time of year: lower than about 89% of the daily flows this gauge has recorded for this date (give or take 7 days) over 99 years of record (1928–2026).
The middle half of those historical flows runs from 332 to 1,400 cfs, with a median of 660 cfs; the lowest 10% of days are at or below 235 cfs and the highest 10% at or above 3,060 cfs.
Over the last 24 hours the flow has been steady (+0.0%). In the last 7 days it ranged from 231 to 256 cfs.
Why this status: Flow is within the range this gauge normally sees at this time of year (or the deviation is too small in absolute terms to matter).
Quick answers
Is the Chehalis River near Grand Mound fishable today?
Flowcast's status for the Chehalis River near Grand Mound is “Fishable/Floatable”: flow is 243 cfs, within the range this gauge normally sees at this time of year, at the 11th percentile for this date (as of Oct 24, 2:00 PM PDT). That describes flow only. It says nothing about water clarity, temperature, fish activity, access or fishing regulations.
What is the current flow of the Chehalis River near Grand Mound?
243 cubic feet per second at USGS gauge 12027500 as of Oct 24, 2:00 PM PDT, provisional data.
Is the Chehalis River near Grand Mound too high or too low right now?
Neither: it is inside the typical range for the date (332 to 1,400 cfs).
Is the Chehalis River near Grand Mound rising or falling?
Over the last 24 hours the flow has been steady (+0.0%).
What is a normal flow for the Chehalis River near Grand Mound in October?
For this date (give or take 7 days) the median is 660 cfs and the middle half of days runs 332 to 1,400 cfs, over 99 years of USGS record.
7-day trend
Hourly flow in cfs, Pacific time. The shaded band is the typical range (25th–75th percentile) for this date, shown when it falls within the chart.
| Day (Pacific) | Mean cfs | Percentile | Status that day |
|---|---|---|---|
| Sun Oct 18 | 247 | 18th | Fishable/Floatable |
| Mon Oct 19 | 249 | 17th | Fishable/Floatable |
| Tue Oct 20 | 232 | 13th | Fishable/Floatable |
| Wed Oct 21 | 246 | 14th | Fishable/Floatable |
| Thu Oct 22 | 243 | 12th | Fishable/Floatable |
| Fri Oct 23 | 242 | 11th | Fishable/Floatable |
| Sat Oct 24 (so far) | 243 | 11th | Fishable/Floatable |
Seasonal context
Shaded band: 10th–90th percentile of daily flows through the year; dashed line: median. Log scale. Dot: today's flow. Based on 99 years of USGS daily data (1928–2026).
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Official resources
- USGS site page for gauge 12027500 (USGS: live readings, history, station details)
- Washington fishing regulations (WDFW)
- Emergency fishing rule changes (WDFW)
- WDFW fishing and stocking reports
Links go to the agencies' own websites and were checked as working. Flowcast does not summarize fishing or boating rules: regulations and closures change, and the agency pages are the authority.
About this gauge
- USGS site
- USGS-12027500
- USGS name
- Chehalis River Near Grand Mound, Wa
- Drainage area
- 895 sq mi
- Location
- 46.7759, -123.0357
- Record in this analysis
- 1928–2026
Nearby gauges
- Toutle River at Tower Road, near Silver Lake, WA Fishable/Floatable 469 cfs · about 32 mi away (straight line)
- Cowlitz River at Castle Rock, WA Fishable/Floatable 4,150 cfs · about 35 mi away (straight line)
- Skokomish River near Potlatch, WA Fishable/Floatable 327 cfs · about 37 mi away (straight line)
- Puyallup River at Puyallup, WA Too low 757 cfs · about 45 mi away (straight line)
- Nisqually River near National, WA Too low 133 cfs · about 45 mi away (straight line)
- Wynoochee River above Save Creek, near Aberdeen, WA Too low 190 cfs · about 46 mi away (straight line)
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