USGS · 06479525

BIG SIOUX RIVER

USGS · 06479525LIVE

Big Sioux R nr Castlewood, SD

HAMLIN COUNTY, SD44.7316°N, -97.0446°W Updated 15 hr ago

FLOW RATE

38cfs

AIR TEMP

63°F

WIND

6mph NNW

FISH INDEX

75SCORE / 100

GREAT · 4 OF 5

1D 7D 30D 1YR

Flow Rate Historical Avg

MEDIAN FLOW RATE · 30 DAY

38cfs 53.1% vs avg

Optimal band: 77–103 cfs

PERIOD HIGH

229cfs

PERIOD LOW

38cfs

RUNNABLE

23%

last 30 day in band

Precipitation History

Your History · Big Sioux R nr Castlewood, SD

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Weather Conditions

WEATHER CONDITIONS

TODAY

73°

51°

FRI

75°

57°

SAT

79°

61°

SUN

99°

69°

MON

96°

76°

TUE

98°

66°

WED

98°

78°

TIME

THU

NOW

FRI

SAT

SUN

MON

TUE

TEMP

hourly forecast

72°

mild

72°

73°

72°

71°

67°

63°

61°

59°

58°

57°

59°

63°

66°

68°

72°

73°

71°

72°

74°

75°

73°

71°

69°

66°

64°

63°

62°

61°

63°

64°

67°

68°

70°

74°

79°

78°

74°

72°

71°

70°

69°

70°

72°

73°

75°

77°

82°

86°

90°

92°

95°

97°

99°

96°

92°

88°

86°

84°

82°

81°

80°

79°

78°

77°

79°

81°

82°

86°

90°

94°

96°

95°

94°

91°

87°

82°

78°

76°

74°

71°

69°

68°

67°

66°

67°

71°

76°

WIND

mph · gust · dir

3mph NNE

G 4 mph

NNE

ENE

G11

G14

ESE

G16

ESE

G14

G12

ESE

G13

ESE

G11

ESE

G12

ESE

G21

SSE

G21

SSE

G16

G14

G15

G13

SSW

G15

SSW

G15

SSE

G18

SSE

G20

SSE

G18

SSE

G19

G18

G15

G16

G18

G19

SSE

G19

SSE

G21

SSE

G26

SSE

G29

SSE

G30

SSE

G34

SSE

G34

SSE

G33

SSE

G30

SSE

G28

SSE

G27

SSE

G27

SSE

G28

SSE

G29

SSE

G30

SSE

G31

SSE

G31

SSE

G31

SSE

G30

SSE

G32

SSE

G32

SSE

G34

G33

SSE

G34

SSE

G36

G34

G32

G33

G34

SSE

G32

SSE

G28

SSE

G25

G24

G22

G21

G22

G24

G29

G31

G33

SSE

G37

SSE

G37

SSE

G38

SSE

G40

SSE

G38

SSE

G39

SSE

G39

SSE

G39

SSE

G37

SSE

G37

G36

G32

G30

SSW

G29

SSW

G27

SSW

G23

G18

G20

WSW

G19

WNW

NNW

NNE

G10

ENE

G13

G15

PRECIP

chance %

13%

14%

20%

33%

28%

19%

22%

16%

CLOUDS

cover %

100%

overcast

100%

23%

94%

100%

57%

98%

100%

86%

100%

78%

15%

20%

12%

21%

40%

16%

28%

53%

61%

100%

60%

49%

100%

80%

100%

69%

17%

100%

32%

54%

100%

99%

100%

81%

54%

39%

46%

64%

PRESSURE

hPa · trend

959

TemperatureWind / GustsPrecipitationCloud coverPressure

Nowscroll →

FISH INDEX

Temperature

Ideal

Wind

Light

Pressure

Stable

Moon Phase

Average

DAYLIGHT

SUNRISE

05:43 AM

SUNSET

09:18 PM

15H 35M OF DAYLIGHT5H 51M REMAINING

MOON PHASE

Waxing Gibbous

80% illuminated

Station Location

44.7316, -97.0446

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DATA · USGS · NOAA · NWSUPDATED 2026-06-25 15:27 UTC

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