National Weather Service California Nevada River Forecast Center Department of Commerce National Oceanic and Atmospheric Administration National Weather Service



TUOLUMNE RIVER - HETCH HETCHY RESERVOIR (HETC1)
Latitude: 37.95º NLongitude: 119.79º WElevation: 3870 Feet
Location: Tuolumne County in CaliforniaBulletin Group: San JoaquinRiver Group: San Joaquin
Issuance Time: Jul 11, 2025 at 8:16 AM PDT
Please Note:Flow data on this product are unregulated / full natural flow.
Historical Flows
RankYearAnnual Flow3-Year Mean
197131536000000703.2
197263072000000523.9
197394694400000801.8 676.3
1974126230400000916.4 747.4
1975157766400000781.7 833.3
1976189302400000293.0 663.7
1977220924800000205.8 426.8
19782524608000001158.8 552.5
1979283996800000723.3 696.0
19803155328000001149.1 1010.4
1981347155200000454.2 775.6
19823786912000001339.5 980.9
19834102272000001645.2 1146.3
19844417632000001025.0 1336.6
1985473385600000538.1 1069.4
19865049216000001178.3 913.8
1987536457600000316.4 677.6
1988567993600000391.4 628.7
1989599616000000622.4 443.4
1990631152000000385.3 466.4
1991662688000000469.6 492.4
1992694224000000355.4 403.4
1993725846400000981.3 602.1
1994757382400000372.1 569.6
19957889184000001458.5 937.3
1996820454400000933.3 921.3
19978520768000001158.4 1183.4
19988836128000001117.0 1069.6
1999915148800000797.5 1024.3
2000946684800000693.5 869.3
2001978307200000455.9 649.0
20021009843200000627.5 592.3
20031041379200000712.8 598.7
20041072915200000596.5 645.6
200511045376000001034.3 781.2
200611360736000001192.5 941.1
20071167609600000368.9 865.3
20081199145600000524.6 695.4
20091230768000000757.6 550.4
20101262304000000822.3 701.5
201112938400000001378.6 986.1
20121325376000000384.4 861.7
20131356998400000469.8 744.3
20141388534400000332.2 395.5
20151420070400000264.8 355.6
20161451606400000785.3 460.8
201714832288000001746.7 932.3
20181514764800000647.9 1060.0
201915463008000001070.1 1154.9
20201577836800000348.6 688.8
20211609459200000278.9 565.9
20221640995200000500.3 376.0
202316725312000001543.3 774.2
20241704067200000617.0 886.9
20251735689600000 559.1 906.5

Location Photographs

ESRI™ Locator Map
Official 7 Day National Weather Service Forecast   (CAZ323)
Tonight: Clear. Lows 48 to 62. Northwest winds up to 10 mph shifting to the east after midnight.

Saturday: Sunny. Highs 71 to 83. Southeast winds up to 10 mph shifting to the southwest in the afternoon.

Saturday Night: Clear. Lows 48 to 62. West winds up to 10 mph shifting to the northeast after midnight.

Sunday: Sunny. Highs 72 to 84. East winds up to 5 mph shifting to the southwest in the afternoon.

Sunday Night: Clear. Lows 49 to 63. West winds up to 10 mph shifting to the northeast after midnight.

Monday through Tuesday Night: Clear. Highs 71 to 86. Lows 45 to 62.

Wednesday: Sunny. Highs 68 to 80.

Wednesday Night: Mostly clear. Lows 43 to 57.

Thursday through Friday: Clear. Highs 65 to 78. Lows 41 to 55.