California · Yosemite Valley, CA

Merced River float season

Gauge 11266500 on the Yosemite Valley bridges and the El Portal canyon below Redbud. Raft rentals drift beneath Half Dome in the Valley while spring snowmelt fuels the canyon runs down Highway 140.

rafttubingkayak Fullest: Apr–Jun Leanest: Sep–Nov
Merced River — typical flow through the year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 300 1.5k 3k 5k
median flow for the date middle half of years (25th–75th percentile) most years (10th–90th)

Right now at this gauge

loading CFS

Checking the live gauge…

Live reading from the USGS gauge page for Merced River. Provisional data — subject to revision.

The year on this river

In a typical year at the Yosemite Valley gauge, the Merced River runs fullest Apr–Jun and leanest Sep–Nov. Where today's reading falls inside that rhythm matters more than the raw number — the same flow that feels thin in spring can be the summer norm. Half of all past May days at this gauge ran above 2,090 CFS; the October median is 30 CFS.

Median of daily flows in each month across this gauge's full record — half of past days ran above these figures, half below.
Month Typical flow (CFS) Relative volume
January 132
February 201
March 352
April 1,095
May 2,090
June 1,480
July 373
August 76
September 34
October 30
November 48
December 85

Record context

This gauge has measured daily flow since 1917 — 109 years of record. The largest daily average ever logged here was 21,000 CFS, in January 1997. Rivers do that sometimes; it's why the safety panel above isn't decoration.

Planning dates? The trip-window checker shows what flows have historically looked like on any week you pick for this river, or see what a CFS actually looks like.

More California float rivers

Common questions

When is the Merced River usually at its fullest?

At the Yosemite Valley gauge, the fullest stretch of a typical year is Apr–Jun, with the single highest monthly median in May (about 2,090 CFS). The leanest months are usually Sep–Nov.

What is a typical summer flow on the Merced River?

The July median at this gauge is about 373 CFS — half of past Julys ran higher, half lower. Check the ribbon chart above to see how summer compares with the rest of the year here.

Is the Merced River safe to float right now?

No flow number can answer that, and this site never labels a river safe. What the data can tell you is how today's reading compares with 109 years of this date's history — well above typical means pushier, colder, faster water. Pair that context with a PFD, a look at the river from the bank, and a call to a local outfitter before you commit.

Which USGS gauge does this page use?

USGS gauge 11266500 (MERCED R A POHONO BRIDGE NR YOSEMITE CA), chosen because it best represents the Yosemite Valley bridges and the El Portal canyon below Redbud. Daily records here reach back to 1917.

Data: USGS gauge 11266500, approved daily records 1917–2026, retrieved 2026-08-07. Live readings are provisional and subject to revision. U.S. Geological Survey data is public domain.