Waterfall flow changes

[nitasue]

I understand that the falls all tend to peak in May and early June and can be almost dry by August but am wondering how much of a difference would there be between mid June and second week of July? We are trying to decide which week to go and that is only one of many variables. It would be easier for us work wise in July but it seems crowds and waterfalls might be better in June....any opinions?? Thanks.

[Phil]

You understand correctly. If you want to catch the falls at their peak, go earlier. It varies annually based on snowpack, El Nino effect, temperature...but generally speaking, snow melt triggers sometime around mid-May and peaks within about 2 weeks or so. You might not hit it exactly, but any time during June is going to be when you're going to see the best flows and get the biggest "WOW" factor out of your experience. Bring rain gear if you want to get up close and personal, especially if you plan on hiking up to the base of Bridalveil.

[Recycling1991]

Last two weeks in May tend to be the best time to see the falls; another big plus is the dogwood is often blooming, though it's the end of the bloom season. would go for mid-June versus second week of July. That said, it's always lovely there. Those of us who voice opinions on what seasons have experienced them all and like some better than others, but it is always beautiful.

If you go mid-July, you may possibly get to go to the high Sierras, Tuolumne area, which will be beautiful then; mosquitoes will be present, so bring bug repellent, but the meadows will be green and gorgeous.

[Dave_Ayers]

The date of peak water flow varies quite a bit depending on the snowfall for the preceding winter. See for instance the graph of the Merced River level at happy isles for 1/1/10 through 1/1/16 (year lines are Jan. 1) at http://nwis.waterdata.usgs.gov/nwisweb/ ... 2016-01-01 .
Note that in the low snow years 2012-2015, the peak flows were in April while in the semi-heavy year 2011 it was in June, a two month spread! So your best bet is to delay trip planning until it is clear how heavy the winter precipitation is.

For more info, see the Yosemite Hydrology page with streamflow links at http://www.nps.gov/yose/learn/nature/hydrology-data.htm .

[Phil]

Peak flows definitely vary somewhat on a year to year basis, but for general schedule and itinerary planning purposes on when to go, what to expect, and where to see it:

http://www.nps.gov/yose/planyourvisit/waterfalls.htm