What is the current flow on Difficult Run?

Difficult Run was running 5 cubic feet per second as of Aug 1, 2026, 6:15 PM UTC, measured at USGS gauge 01646000. This is a build-time snapshot rather than a live reading — check the USGS gauge directly before relying on it.

What is the water temperature on Difficult Run?

76.8°F (24.9°C) as of Aug 1, 2026, 6:15 PM UTC, at USGS gauge 01646000. Difficult Run carries no state trout classification, so the trout-stress thresholds do not apply to it — this is a water temperature measurement, not a fishery judgement.

Difficult Run

Virginia. Streamflow and water-temperature readings from USGS gauges. Running 5 cfs as of Aug 1, 2026, 6:15 PM UTC.

Latest Reading

cubic feet / second

76.8°F

water temperature (24.9°C)

USGS gauges

Flow measured Aug 1, 2026, 6:15 PM UTC at gauge 01646000. Temperature measured Aug 1, 2026, 6:15 PM UTC at gauge 01646000. These are build-time snapshots, not a live feed — check the USGS gauge before relying on them.

USGS Gauges on Difficult Run

Gauge	Station	Water temp?
01645704	DIFFICULT RUN ABOVE FOX LAKE NEAR FAIRFAX, VA	Yes
01646000	DIFFICULT RUN NEAR GREAT FALLS, VA	Yes

Fly fishing rivers →Virginia lakes →

Conditions: USGS NWIS (public domain).