USGS · 01646000

DIFFICULT RUN

USGS · 01646000LIVE

DIFFICULT RUN NEAR GREAT FALLS, VA

RESTON, VA38.9759°N, -77.2458°W Updated 37 min ago

FLOW RATE

28.7cfs

GAUGE HT

2.97ft

WATER TEMP

77°F

AIR TEMP

74°F

WIND

5mph NNE

FISH INDEX

63SCORE / 100

GOOD · 3 OF 5

1D 7D 30D 1YR

Flow Rate Historical Avg

MEDIAN FLOW RATE · 1 DAY

28.7cfs 173.4% vs avg

Optimal band: 56–75 cfs

PERIOD HIGH

695cfs

PERIOD LOW

28.7cfs

RUNNABLE

11%

last 1 day in band

Gauge Height

2.97ft

Water Temperature

77.2°F

Water Turbidity

Precipitation History

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Weather Conditions

WEATHER CONDITIONS

TODAY

87°

73°

MON

87°

65°

TUE

91°

67°

WED

100°

71°

THU

98°

78°

FRI

92°

75°

SAT

92°

69°

TIME

SUN

NOW

MON

TUE

WED

THU

FRI

TEMP

hourly forecast

75°

mild

75°

76°

78°

81°

83°

84°

85°

86°

87°

86°

85°

80°

77°

74°

73°

71°

69°

68°

67°

66°

65°

67°

71°

75°

78°

81°

83°

85°

86°

87°

86°

84°

80°

77°

75°

74°

72°

71°

70°

69°

68°

67°

68°

72°

76°

80°

84°

86°

88°

90°

91°

90°

89°

84°

80°

79°

77°

76°

74°

73°

72°

71°

72°

76°

81°

85°

89°

92°

95°

97°

99°

100°

97°

91°

87°

86°

85°

83°

82°

81°

80°

79°

78°

79°

82°

85°

88°

90°

93°

96°

98°

97°

91°

90°

94°

91°

86°

84°

82°

80°

79°

77°

76°

WIND

mph · gust · dir

7mph ENE

G 15 mph

G15

ENE

G14

ENE

G13

ENE

G12

G11

G10

G11

ESE

G12

ESE

G13

ESE

G16

G11

G10

ESE

ENE

NNE

G10

G11

G10

ESE

G10

G11

G10

ESE

G14

SSE

G13

G10

SSW

WNW

NNW

WSW

SSW

G11

SSW

G17

SSW

G18

SSW

G16

G13

G11

WSW

G11

G12

WNW

G13

WNW

G13

G11

WNW

G10

WNW

G11

G12

G10

NNW

G11

WNW

G17

G15

G16

G14

G15

G16

WNW

G17

WNW

G17

WNW

G17

NNW

G17

NNW

G17

G19

NNW

G19

G21

NNW

G23

NNW

G24

NNW

G24

NNW

G21

NNW

G17

NNW

G13

NNW

PRECIP

chance %

12%

15%

CLOUDS

cover %

100%

overcast

100%

62%

100%

84%

100%

75%

100%

87%

10%

100%

98%

100%

96%

62%

100%

52%

12%

91%

29%

59%

100%

36%

18%

51%

63%

85%

100%

98%

89%

83%

PRESSURE

hPa · trend

1011

TemperatureWind / GustsPrecipitationCloud coverPressure

Nowscroll →

FISH INDEX

Temperature

Warm

Wind

Light

Pressure

Rising — Slow

Moon Phase

Average

DAYLIGHT

SUNRISE

05:53 AM

SUNSET

08:35 PM

14H 42M OF DAYLIGHT

MOON PHASE

Waning Crescent

7% illuminated

Station Location

38.9759, -77.2458

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DATA · USGS · NOAA · NWSUPDATED 2026-07-12 07:15 UTC

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