USGS · 01645704

DIFFICULT RUN

USGS · 01645704LIVE

DIFFICULT RUN ABOVE FOX LAKE NEAR FAIRFAX, VA

RESTON, VA38.8847°N, -77.3324°W Updated 11 hr ago

FLOW RATE

2cfs

AIR TEMP

71°F

WIND

5mph NNE

FISH INDEX

81SCORE / 100

GREAT · 4 OF 5

1D 7D 30D 1YR

Flow Rate Historical Avg

MEDIAN FLOW RATE · 30 DAY

2cfs 55.0% vs avg

Optimal band: 2–2 cfs

PERIOD HIGH

17cfs

PERIOD LOW

1cfs

RUNNABLE

39%

last 30 day in band

Precipitation History

Your History · DIFFICULT RUN ABOVE FOX LAKE NEAR FAIRFAX, VA

Track your history

Sign in to track your sessions at DIFFICULT RUN ABOVE FOX LAKE NEAR FAIRFAX, VA — best days, monthly trends, and time on the water.

SPONSORED

Weather Conditions

WEATHER CONDITIONS

TODAY

78°

71°

MON

83°

68°

TUE

94°

68°

WED

99°

70°

THU

103°

78°

FRI

105°

80°

SAT

104°

70°

TIME

SUN

NOW

MON

TUE

WED

THU

FRI

TEMP

hourly forecast

74°

mild

74°

75°

77°

78°

77°

75°

74°

72°

71°

69°

68°

69°

72°

73°

75°

77°

79°

80°

82°

83°

82°

81°

78°

75°

73°

72°

71°

70°

69°

68°

70°

73°

77°

81°

84°

87°

89°

91°

93°

94°

93°

89°

76°

73°

71°

70°

71°

72°

71°

72°

76°

81°

86°

90°

94°

97°

99°

98°

95°

90°

87°

84°

83°

82°

81°

80°

78°

80°

84°

88°

92°

95°

97°

99°

101°

103°

102°

101°

99°

94°

90°

88°

87°

85°

84°

83°

82°

80°

81°

WIND

mph · gust · dir

4mph NE

G 6 mph

NNE

G11

G10

NNE

G10

NNW

NNE

ENE

ESE

G15

G12

G15

SSE

G15

SSE

G15

SSE

G14

G16

SSW

G16

SSW

G15

SSW

G12

SSW

G13

G11

G10

SSW

G11

SSE

G15

SSE

G17

G18

G20

G27

SSW

G28

SSW

G27

SSW

G26

SSW

G19

SSW

G11

SSW

WSW

WNW

NNW

NNE

ENE

SSW

WSW

WNW

G11

NNW

NNE

NNW

ENE

ESE

G12

G15

G18

WNW

G20

WNW

G19

WNW

PRECIP

chance %

29%

25%

28%

18%

16%

15%

18%

19%

12%

11%

10%

CLOUDS

cover %

100%

overcast

100%

68%

54%

100%

87%

55%

86%

47%

100%

15%

96%

73%

100%

56%

100%

96%

46%

33%

88%

18%

37%

10%

14%

82%

100%

54%

76%

92%

90%

10%

75%

47%

91%

96%

91%

30%

80%

100%

17%

32%

10%

31%

100%

80%

100%

65%

88%

11%

100%

41%

100%

16%

35%

73%

96%

84%

PRESSURE

hPa · trend

1003

TemperatureWind / GustsPrecipitationCloud coverPressure

Nowscroll →

FISH INDEX

Temperature

Warm

Wind

Light

Pressure

Stable

Moon Phase

Peak Activity

DAYLIGHT

SUNRISE

05:46 AM

SUNSET

08:38 PM

14H 52M OF DAYLIGHT8H 53M REMAINING

MOON PHASE

Full Moon

97% illuminated

PEAK ACTIVITY

Station Location

38.8847, -77.3324

Loading map…

DATA · USGS · NOAA · NWSUPDATED 2026-06-28 11:45 UTC

Site #01645704·USGS

Create a free account to save favorites, set flow alerts, and track conditions