Waterlands
Difficult Run
USGS · 01646000
DIFFICULT RUN
USGS · 01646000LIVE

DIFFICULT RUN NEAR GREAT FALLS, VA

RESTON, VA38.9759°N, -77.2458°W Updated 9 hr ago
FLOW RATE
34cfs
GAUGE HT
3.04ft
WATER TEMP
78°F
AIR TEMP
73°F
WIND
3mph NNE
FISH INDEX
69SCORE / 100
GREAT · 4 OF 5
Flow Rate Historical Avg
MEDIAN FLOW RATE · 30 DAY
34cfs 33.9% vs avg
Optimal band: 12–16 cfs
PERIOD HIGH
158cfs
PERIOD LOW
7cfs
RUNNABLE
19%
last 30 day in band

Gauge Height

3.04ft

Water Temperature

77.7°F

Water Turbidity

Precipitation History
Your History · DIFFICULT RUN NEAR GREAT FALLS, VA

Track your history

Sign in to track your sessions at DIFFICULT RUN NEAR GREAT FALLS, VA — best days, monthly trends, and time on the water.

Sign in
SPONSORED
Weather Conditions
WEATHER CONDITIONS
TODAY
84°
73°
MON
88°
65°
TUE
91°
67°
WED
100°
71°
THU
98°
78°
FRI
92°
75°
SAT
92°
69°
TIME
SUN
9
NOW
10
am
11
am
12
pm
1
pm
2
pm
3
pm
4
pm
5
pm
6
pm
7
pm
8
pm
9
pm
10
pm
11
pm
MON
12
am
1
am
2
am
3
am
4
am
5
am
6
am
7
am
8
am
9
am
10
am
11
am
12
pm
1
pm
2
pm
3
pm
4
pm
5
pm
6
pm
7
pm
8
pm
9
pm
10
pm
11
pm
TUE
12
am
1
am
2
am
3
am
4
am
5
am
6
am
7
am
8
am
9
am
10
am
11
am
12
pm
1
pm
2
pm
3
pm
4
pm
5
pm
6
pm
7
pm
8
pm
9
pm
10
pm
11
pm
WED
12
am
1
am
2
am
3
am
4
am
5
am
6
am
7
am
8
am
9
am
10
am
11
am
12
pm
1
pm
2
pm
3
pm
4
pm
5
pm
6
pm
7
pm
8
pm
9
pm
10
pm
11
pm
THU
12
am
1
am
2
am
3
am
4
am
5
am
6
am
7
am
8
am
9
am
10
am
11
am
12
pm
1
pm
2
pm
3
pm
4
pm
5
pm
6
pm
7
pm
8
pm
9
pm
10
pm
11
pm
FRI
12
am
1
am
2
am
3
am
4
am
TEMP
hourly forecast
76°
mild
76°
77°
80°
81°
81°
83°
84°
82°
82°
84°
82°
80°
78°
76°
74°
72°
71°
69°
68°
67°
66°
65°
67°
72°
76°
79°
82°
84°
86°
87°
88°
88°
88°
87°
86°
83°
80°
77°
76°
74°
72°
70°
69°
68°
68°
67°
68°
72°
76°
80°
84°
86°
88°
90°
91°
91°
91°
90°
89°
84°
80°
79°
77°
76°
74°
73°
72°
72°
71°
71°
72°
76°
81°
85°
89°
92°
95°
97°
99°
99°
100°
100°
97°
91°
87°
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°
75°
75°
WIND
mph · gust · dir
8mph ENE
G 13 mph
8
G13
ENE
8
G14
ENE
9
G13
E
9
G13
E
8
G11
ENE
8
G11
NE
7
G10
NE
6
G9
NNE
4
G9
NE
5
G9
ESE
4
G10
ESE
6
G15
SE
6
G14
SE
5
G11
SE
4
G12
SE
2
G9
ESE
3
G10
SE
2
G9
SSW
2
G6
N
3
N
4
N
2
ENE
1
G2
NE
2
G3
E
2
G6
SE
4
G7
SE
3
G5
SE
2
G3
ESE
2
G3
SE
5
G6
S
6
G7
S
6
G8
SSW
6
G8
SSW
6
G8
SSW
5
G6
SW
5
G9
SSW
5
G10
S
5
G13
S
6
G15
S
5
G14
S
5
G12
SSW
4
G10
SSW
4
G8
SSW
3
G4
WNW
3
W
3
G4
NW
3
N
1
G2
NNW
1
WSW
1
WSW
2
SSW
3
SSW
4
SSW
4
SW
4
SW
5
SW
5
SW
4
G5
SW
5
G7
SW
4
G7
SW
5
G9
SSW
5
G11
SSW
6
G17
SSW
6
G18
SSW
5
G16
SW
5
G13
SW
4
G11
SW
4
G6
WSW
4
G6
W
4
G6
W
4
G9
W
5
G11
W
6
G12
WNW
7
G13
WNW
8
G13
NW
8
G11
WNW
7
G9
W
7
G9
WNW
7
G9
WNW
7
G10
WNW
6
G11
W
5
G12
W
4
G12
NW
5
G10
N
2
NNW
3
W
4
G5
W
4
G8
W
4
G11
WNW
6
G17
NW
6
G17
NW
5
G15
NW
5
G16
NW
5
G14
NW
4
G15
NW
6
G15
NW
7
G15
NW
9
G15
NW
10
G16
NW
9
G16
WNW
9
G17
WNW
10
G17
WNW
12
G17
NNW
11
G17
NNW
8
G17
NW
10
G19
NNW
10
G19
N
7
G21
NNW
7
G23
NNW
8
G24
NNW
8
G24
NNW
7
G21
NNW
5
G17
NNW
4
G13
NNW
4
G12
NNW
4
G12
NNW
PRECIP
chance %
4%
4%
5%
5%
4%
5%
6%
10%
13%
8%
4%
3%
1%
1%
1%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
1%
1%
1%
1%
1%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
1%
1%
1%
1%
1%
1%
2%
2%
2%
2%
2%
2%
6%
6%
6%
6%
6%
6%
1%
1%
1%
1%
1%
1%
0%
0%
0%
0%
0%
0%
2%
2%
2%
2%
2%
2%
7%
7%
7%
7%
7%
7%
8%
8%
CLOUDS
cover %
100%
overcast
100%
100%
93%
100%
97%
100%
100%
100%
100%
100%
100%
100%
100%
100%
46%
86%
46%
100%
82%
100%
100%
99%
15%
3%
3%
2%
0%
0%
28%
37%
27%
27%
17%
9%
8%
0%
0%
0%
0%
27%
89%
75%
100%
100%
100%
100%
100%
0%
0%
5%
5%
87%
6%
0%
5%
5%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
10%
0%
6%
0%
100%
98%
100%
96%
62%
100%
52%
12%
91%
29%
59%
100%
100%
36%
18%
51%
63%
85%
100%
98%
89%
83%
86%
92%
PRESSURE
hPa · trend
1012
10121012101310131015101310131013101410101009100710081004100310031005100310041007
TemperatureWind / GustsPrecipitationCloud coverPressure
Nowscroll →
FISH INDEX
69
Temperature
Warm
Wind
Calm
Pressure
Rising — Slow
Moon Phase
Average
DAYLIGHT
SUNRISE
05:53 AM
SUNSET
08:35 PM
14H 42M OF DAYLIGHT
MOON PHASE
Waning Crescent
6% illuminated

Station Location

38.9759, -77.2458
Loading map…
DATA · USGS · NOAA · NWSUPDATED 2026-07-12 00:00 UTC
Site #01646000·USGS

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

Sign up free