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

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MERCED RIVER - YOSEMITE NP AT HAPPY ISLES (HPIC1)
Latitude: 37.73º NLongitude: 119.56º WElevation: 4017 Feet
Location: Mariposa County in CaliforniaBulletin Group: San JoaquinRiver Group: San Joaquin
Issuance Time: Jul 02 2025 at 8:28 AM PDTNext Issuance: Jul 03 2025 at 9:00 AM PDT
Action/Monitor: N/A Minor Flood: 7.5 FeetModerate Flood: 10.0 FeetMajor Flood: 13.27 Feet

Please Note:
1) Each individual timeseries plotted on the graphical river forecast can be toggled on and off by clicking the legend entry above. If the "Observed (Raw Data)" contains bad data and is toggled off, the plot will scale to the remaining timeseries.

2) At extremely low river flows, the "Observed (Raw Data)" may show readings below the lower end of the available rating table, while the "Observed (Simulated)" will only show values at the bottom of the rating table, creating a potential discrepancy between the two readings.
Observed Data Credit
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Raw streamflow data is provided by the US Geological Survey (USGS).
View US Geological Survey (USGS) Data for this station location.

Verification - Historical Graphical RVF
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To view other verification locations, use our Historical Graphical River Forecast Interface.
Historical Stage/Flow Data
Water Year
Peak Discharge (cfs)
Stage (feet)
Date
 Most Recent 5 Years
2024
2,980
6.80
May 19, 2024
2023
4,980
8.42
May 23, 2023
2022
2,430
6.25
Oct 25, 2021
2021
1,410
5.02
May 7, 2021
2020
2,160
5.96
Apr 30, 2020
 Historical High Stage/Flow Events (Period of Record - Aug 1915 to Present) - Ranked by Flow
1997
10,100
13.27
Jan 2, 1997
1956
9,840
12.73
Dec 23, 1955
1951
9,260
11.55
Nov 18, 1950
Location Photographs
ESRI™ Locator Map
Flood Impacts
13.27 FeetFlood of Record: 1/2/97. $178 million in damage to Yosemite Valley.
10.0 FeetNorthside Drive at Wosky Pond, Southside Drive at Chapel Meadow, El Capitan crossover, and Sentinel crossover are impassable to vehicles.
8.2 FeetSwinging Bridge overtops. Water on road at Northside Drive, Southsie Drive, El Capitan crossover, and Sentinel crossover.
7.5 FeetFlood Stage. Housekeeping camp and Yosemite Valley backpacker campground begin to flood.
7.0 FeetNorth Pines and Lower Pines campgrounds begin flooding.
Official 7 Day National Weather Service Forecast   (CAZ324)
Today: Sunny. Slight chance of rain late in the morning. Slight chance of thunderstorms in the afternoon. Highs 76 to 90. Southwest winds up to 5 mph increasing to 5 to 15 mph in the afternoon. Chance of precipitation 20 percent.

Tonight: Partly cloudy with a 20 percent chance of thunderstorms in the evening, then clear after midnight. Lows 58 to 66. West winds up to 10 mph shifting to the east after midnight.

Thursday: Sunny. Highs 77 to 89. South winds up to 10 mph shifting to the southwest in the afternoon.

Thursday Night: Cooler. Mostly clear. Lows 51 to 59. Southwest winds 5 to 10 mph shifting to the east after midnight.

Independence Day: Sunny. Highs 69 to 83. South winds up to 5 mph increasing to southwest 10 to 15 mph in the afternoon.

Friday Night through Monday: Clear. Lows 51 to 64. Highs 74 to 93.

Monday Night and Tuesday: Clear. Lows 59 to 67. Highs 82 to 94.
Product Disclaimer

This river graphic is not intended to serve as a substitute for official flood watches, warnings, advisories, or statements issued by the NWS San Joaquin Valley-Hanford Weather Forecast Office. Observations are preliminary and subject to change. River levels identified as "forecast" should be consistent with those contained in official NWS products. River levels identified as "guidance" have significant uncertainty due to future weather or reservoir regulation and are provided for planning purposes only.