Au Sable River Fly Fishing Report
Grayling, Crawford County, Michigan · Last Updated: July 16, 2026
The Au Sable River is Michigan's most beloved fly fishing destination and one of the premier trout streams in the Midwest. The Holy Water catch-and-release section near Grayling is famous for its exceptional hex hatch — the largest mayfly in North America.
Today's Trout Fishability
Conditions at a Glance
Flows on Au Sable branches near Grayling are below normal, with the South Branch at 209 cfs (-44% vs average) and North Branch at 251 cfs (-22%).
- Water temperature varies 64.6–68.2°F across gauges — warmer reaches are stressing trout; fish the cooler water and early.
- High, off-color water
How Do You Fish a 6.2/10 Day?
See the fly patterns built for today's conditions, where the fish are holding, and how to work the 5:30 AM - 9:00 AM, 6:00 PM - 8:00 PM window.
Today's Weather
See hourly conditions, wind speeds, barometric pressure, and 5-day outlook
USGS Water Monitoring
Real-time data from 2 monitoring stations
See station-by-station details, historical ranges, and trend analysis
What's Hatching This Month
Upper Midwest & Driftless — typical for July
6.2/10 Today — See the Full Au Sable River Breakdown
Free account unlocks fly patterns, a hatch forecast, and tactics matched to today's exact flows. 3 reports a month, no credit card.
Au Sable River Fly Fishing — FAQ
Is the Au Sable River fishing well right now?
DriftWise scores the Au Sable River every morning on a 0–10 fishability scale that weighs real-time USGS flow and water temperature, National Weather Service forecasts, and lunar data. Check the live fishability score and condition summary above for today's rating before you head out.
What is the current water flow on the Au Sable River?
The Au Sable River's flow is tracked by USGS streamflow gauges near Grayling, Crawford County, Michigan and refreshed daily in the condition summary above. Flow is reported in cubic feet per second (cfs) and compared against the seasonal average so you can see whether the river is running high, low, or normal.
What is a good water temperature for trout on the Au Sable River?
Trout feed most actively when water temperatures sit roughly between 48°F and 62°F. DriftWise reads live Au Sable River water temperature from USGS sensors near Grayling, Crawford County, Michigan — see the summary above for the current value.
When is the best time of day to fish the Au Sable River?
The most productive windows shift with the season: cold months fish best around midday (10 AM–2 PM) once the water warms, while summer rewards early mornings and evenings. Each Au Sable River report factors in the current season.
Do I need a fishing license to fly fish the Au Sable River?
Yes. A valid Michigan fishing license is required to fish the Au Sable River. Check current Michigan regulations for seasons, limits, and any special catch-and-release or fly-fishing-only sections before you go.
Is the DriftWise Au Sable River fishing report free?
Yes. The daily Au Sable River condition summary — flow, water temperature, weather, and fishability score — is free. A free account (3 reports per month) unlocks the full AI analysis with fly-pattern recommendations and a detailed hatch forecast.
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