Station Name: DIFFICULT RUN ABOVE FOX LAKE NEAR FAIRFAX, VA
Data Source: Water Data - usgc.gov

Elevation Above Sea Level: 328 feet

Nearest Address:
11200 Lapham Dr
Oakton, VA 22124
Fairfax County

GPS Coordinates: 38.88469518, -77.3324293

Nearby Water Temperatures

Heat Advisory issued July 18 at 7:50AM EDT until July 18 at 7:00PM EDT by NWS Baltimore MD/Washington DC

Effective: Sat July 18, 2026, 7:50 AM
Expires: Sat July 18, 2026, 7:00 PM

* WHAT...Heat index values around 105 expected. * WHERE...Washington DC, and portions of central, northern, and southern Maryland, and central and northern Virginia. * WHEN...From 11 AM this morning to 7 PM EDT this evening. * IMPACTS...Hot temperatures and high humidity may cause heat illnesses.

Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors. Take extra precautions when outside. Wear lightweight and loose fitting clothing. Try to limit strenuous activities to early morning or evening. Take action when you see symptoms of heat exhaustion and heat stroke. To reduce risk during outdoor work, the Occupational Safety and Health Administration recommends scheduling frequent rest breaks in shaded or air conditioned environments. Anyone overcome by heat should be moved to a cool and shaded location. Heat stroke is an emergency! In cases of heat stroke, call 9 1 1.

Flood Watch issued July 18 at 11:43AM EDT until July 18 at 8:00PM EDT by NWS Baltimore MD/Washington DC

Effective: Sat July 18, 2026, 11:43 AM
Expires: Sat July 18, 2026, 7:45 PM

A slow-moving front will interact with a very humid airmass in place to result in multiple rounds of showers and thunderstorms this afternoon and evening. * WHAT...Flash flooding caused by excessive rainfall continues to be possible. * WHERE...Washington DC, and portions of Maryland, including the following areas, Anne Arundel, Carroll, Cecil, Central and Southeast Howard, Central and Southeast Montgomery, Frederick, Northern Baltimore, Northwest Harford, Northwest Howard, Northwest Montgomery, Prince Georges, Southeast Harford and Southern Baltimore, and northern Virginia, including the following areas, Arlington/Falls Church/Alexandria, Eastern Loudoun, Fairfax and Western Loudoun. * WHEN...From 2 PM this afternoon through 8 PM EDT this evening. * IMPACTS...Excessive runoff may result in flooding of rivers, creeks, streams, and other low-lying and flood-prone locations. Flooding may occur in poor drainage and urban areas. * ADDITIONAL DETAILS... - High humidity coupled with a slow-moving front is expected to result in multiple rounds of showers and thunderstorms this afternoon and evening. Localized rainfall rates of up to 2 inches per hour, with isolated totals of 2 to 4 inches are possible. - Please visit www.weather.gov/safety/flood for flood safety and preparedness information.

You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued.