September 13, 2021
General Conditions
September brings warm breezes, cooler nights and some clear skies for stargazing. For those heading out backpacking, finding available water and staying warm in the evenings may be the hardest part of your trip planning. Seasonal streams are dry and smaller bodies of water are showing stagnation, while major lakes and rivers remain clear and flowing. Smoke is currently minimal and has been for the last few weeks, but conditions can change at any time. See the current smoke and air quality reports.
Yosemite Valley will hover around 90F degree highs for the second weekend of September and beyond, and have lows between 50-60 F with some breezy nights. Tuolumne Meadows expects highs in the low 70’s and lows between 30-40 F at night. Expect temperatures to be closer to average for September, gradually cooling through the month. September can bring early season storms, though they are generally mild bringing cooler temperatures and typically only dusty of snow at the highest elevations and light rain elsewhere. Hikers should come prepared for myriad conditions in the Wilderness. Monitor local weather forecasts before going on a hike.
The park has seen around 30 small fires start from lightning strikes this summer though none are safety concerns besides the Lukens and Tilltill fires. Trail closures are in place in those regions. Hikers in the vicinity may see and hear active firefighter operations, particularly at nearby water sources such as Lake Vernon. Check out our Fire Information page for up-to-date info on the fires and the Closure Page for current safety closures.
As fall approaches the black bears in Yosemite National Park will begin to enter into hyperphagia. In hyperphagia, bears can consume up to 20,000 calories a day! Summer food sources are drying up or finishing while the fall acorn season is just getting started, so bears are in a heightened search of food. Backpackers must be vigilant about storing all scented items properly in an allowed hard sided bear canister. Store bear canisters outside backpacks to avoid property damage and never leave food unsecured. As bears enter hyperphagia, they can become more opportunistic when it comes to finding food, including hikers and backpackers food that is not properly stored. Ensure that you do your part as a steward of the wilderness and make sure all scented items are stored properly at all times.
See a map of trails that have been cleared of downed trees for the season. Please note that although most tree failures occur during the stormy winter months, trees can fail at any time.
Harmful Algal Blooms and Water Quality
Recent testing yielded positive results for small amounts of toxic algae in Tenaya Creek in Yosemite Valley, and toxic algae may exist in other sites in Yosemite Valley. Toxins are concentrated within the algal mats themselves and released episodically into the water when the algae dies or is disturbed.
Can I still swim in the river? Can I still filter or treat the water for drinking?
Water that is clear with no visible algae in the area presents a low risk. Even in areas with no visible algae, watch for isolated clumps of algae floating by.
If you think algae may be in the water:
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Do not enter the water.
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Do not drink the water, even if treated.
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Do not let pets into the water, allow them to drink the water, or eat algae on the shore.
Learn more on our public health page.
| Park Area |
Trails (landmarks included in description) |
Conditions |
| North and South Rim of Yosemite Valley |
Lehamite Creek, North Dome, Dewey Point, McGurk Meadow |
Trails are clear and dry.
Water is available only from major creeks.
Yosemite Creek is 6’ wide and 6" deep.
Yosemite Creek is dry at the campground.
Lehamite Creek is 2' wide and 6" deep
Porcupine Creek is not flowing but has water in pools.
Snow Creek at the footbridge is 6' wide and 1' deep
Creek NW of Mt Watkins is 1' wide and 2" deep.
Bridalveil Creek at the footbridge is 10' wide and 10" deep.
Royal Arch Creek, Meadow Brook and the Southern inlet of Bridalveil Creek are dry.
The camping closure between the top of the Snow Creek switchbacks and the Snow Creek footbridge is still in effect: there is no camping allowed in that area, and camping along Snow Creek is discouraged. Hiking past Snow Creek and finding campsites west of Indian Ridge is strongly advised. |
| Glacier Point Rd |
Ostrander Lake, Illilouette Creek, Red Peak Pass |
Trails are clear and dry.
Water is available only from major creeks
Illilouette Creek (at main junctions) is 20' wide and 10" deep.
Trail to Ostrander Lake has no available water except Bridalveil Creek to the west.
Edson Lake and Hart lakes Creeks are dry.
Buena Vista Creek is dry at crossings (8 miles with no water available).
Creeks from Merced Pass lakes are dry until Ottoway Creek confluence.
Illilouette Creek Eastern Crossing is 15' wide and 10' deep.
Red Creek and Clark Fork are is 10' wide and 5" deep. |
| Wawona Area |
Chilnualna Creek, Buena Vista Loop |
Water is available only from major creeks, smaller streams are likely dry.
Chilnualna Creek is not flowing, water is available from pools near the top of Chilnualna Falls.
No water between Buena Vista Lake and the top of Chilnualna Falls going the north route past Chilnualna Lakes and towards Turner Meadow - about 10 miles.
Johnson Creek (South of Buena Vista Pass) is 2' wide and 4" deep.
Buck and Givens Creeks are dry.
Spring at Buck Camp is flowing
South Fork Merced by Chain Lakes Junction is 6' wide and 5" deep.
South Fork Merced in Moraine Meadows is 15' wide and 2" deep.
Creek on south side of Merced Pass is 2' wide and 4" deep.
Mosquito Creek is dry.
Alder Creek crossing is 5' wide and 2" deep
There is significant trail damage from fallen trees on the trail along Chilnualna Creek, NE from the top of Chilnulna Falls. For .5 miles the trail is completely obscured. |
| Hetch Hetchy |
Beehive Meadows, Laurel Lake, Jack Main Canyon, Wilma Lake. |
Trails are hot and dry with several downed trees.
Water is available mostly from lakes.
Kibbie Creek and Frog Creek are dry.
Falls Creek is flowing.
Water is available is Grace Meadow.
Water is available from two, small, unnamed lakes at the junction 1.8 miles SE of Wilma Lake. After this point, there is no water available until Stubblefield Canyon.
See closures page for info about the Tilltill fire, between Lake Vernon and Tiltill Valley. |
| Tuolumne Area: South of Tioga Rd |
Lyell Canyon, Rafferty Creek, Echo Creek, Fletcher Creek |
Trails are clear and dry.
Water is available only from major creeks and smaller streams are dry.
Cathedral Fork of the Merced and Echo Creek are flowing.
Rafferty Creek is not flowing but has occasional pools.
Ireland Creek is 8' wide and 5" deep.
Emeric Creek and Fletcher Creek are both 4' wide and 5" deep.
Lewis Creek and Florence Creek are both 10' wide and 5" deep.
No water between Cloud's Rest and Sunrise Creek junction.
Outlets of Mildred Lake and the Sunrise Lakes are all dry at the trail crossings.
There is no water available at Sunrise High Sierra Camp. |
| Tuolumne Area: North of Tioga Rd |
Glen Aulin, Cold Canyon, May Lake, Cathedral Creek |
Trails are clear and dry.
Water is available in most named creeks.
Rancheria Creek and Thompson Creek are 3' wide and 6" deep
Stubblefield Creek is 20' wide and 6" deep.
A small spring is flowing between Stubblefield Canyon and Kerrick Canyon, on the north side of the trail, midway on the switchbacks near Stubblefield.
Upper Kerrick Canyon is dry.
Water is available at Seavey Pass.
Tilden Outlet is dry.
Falls Creek crossing near Wilma Junction is 25' wide and 6" deep.
There is no water between Benson Lake and Smedberg Lake.
Water is available in the meadow west of Benson Pass.
Wilson, Matterhorn, Spiller, and Return Creeks are all reliable water sources at this time.
Cold Canyon has no flowing water.
Delaney Creek is 3' wide and 2" deep.
Dingley Creek is dry |
| Tioga Rd: West |
Half Moon Meadow, Ten Lakes, South Fork Cathedral Creek, May Lake |
Trails are clear and several trees are down across the trail.
Water is available from most major sources but smaller streams are likely dry.
South Fork of Cathedral Creek is trickling with pools.
Small creeks north of Tuolumne Peak were trickling as of 8/28/21.
See closures page for info about the Lukens Fire.
May lake bathrooms are open. The road to the May Lake Trailhead is open. |
| John Muir Trail (JMT) - Happy Isles to Donohue Pass |
Little Yosemite Valley, Sunrise Creek, Donohue Pass |
Trail is clear and dry.
Merced River flows year-round. Sunrise Creek at the JMT junction to Clouds Rest is 1' wide and 2" across.
Spring NE of Moraine Dome is flowing across trail 3' wide and 2" deep
Sunrise Creek (eastern crossing) is 2' wide and 2" deep.
Sunrise Creek at base of switchbacks is flowing from a spring 1' wide and 1" deep.
Sunrise Creek is otherwise not flowing.
Sunrise HSC and nearby creeks are totally dry. There is stagnant, brown water in the meadow.
Up to 7 miles without water available between Sunrise Creek and Cathedral Lakes.
Bears are active throughout the very busy JMT corridor in Yosemite. Make sure all your food fits into your bear canister and store properly throughout your trip.
Tuolumne Meadows Backpackers camp is open until Sept 20. |
Current Closures
For more details, and all current trail closures, are listed on the current conditions page.
Full or partial meadow closures to free-range grazing are in effect at Crescent Lake, Hook Lake North, Isberg Lake, Miller Lake, Rodger's Lake, Turner Meadow, and Upper Kerrick Meadow to align with the 2020 Biological Opinion for Yosemite toads and mountain yellow-legged frogs, and Virginia Canyon - Castle Camp for protection of sensitive vegetation resources. Further guidance is provided in the Superintendent's Compendium; detailed maps of meadow closures are at the stock use page.
Trails in Yosemite may be closed when there are hidden hazards or are impassable due to rock fall, snow, ice, or fire. Open trails are not necessarily free of hazards. By entering the wilderness, you are assuming responsibility for your safety and must use good judgment.
Wilderness Permits
Wilderness permits are required for overnight stays in the Yosemite Wilderness and must be reserved online a minimum of four days ahead of your entry date. No first-come, first-served permits are available in Yosemite in 2021.
Wilderness Permit Reservations
Online (help desk available Monday through Friday, 8:30 am to 4:30 pm). Reservations are available up to 24 (168 Days) weeks ahead of your entry date.
Reservations must be picked up between 8 am and 5 pm from one of the following locations:
Yosemite Valley Wilderness Center
Open every day (8 am to 5 pm) for permit pick-up and bear canister rental. Wilderness maps, bear canisters, and other items for purchase are available at the Valley Visitor Center.
Tuolumne Meadows Wilderness Center
Open every day (8 am to 5 pm) for permit pick-up and bear canister rental.
Big Oak Flat Information Station
Open every day (8 am to 5 pm) for permit pick-up and bear canister rental.
Wawona Visitor Center at Hill's Studio
Open every day (8 am to 5 pm) for permit pick-up and bear canister rental.
Hetch Hetchy Entrance Station
Hetchy Road is open 8 am to 5 pm. Wilderness permits for the Hetch Hetchy area and bear canister rentals are available at the entrance station. There is no access to Hetch Hetchy beyond open hours (overnight parking is permitted in the overnight parking lot near the backpackers campground).
Food Storage
Bear resistant food canisters are required in the Yosemite Wilderness. Use a canister to store all food or scented items when left unattended. Remember that anything used in, on, or around the body is considered a food item. Whenever food or scented items are out, please keep them within arm's reach, even while day hiking.
If a bear approaches your camp, act immediately to scare it away. Maintain a safe distance while making as much noise as possible. Throw small stones or pines cones toward the bear, being careful not to strike the bear on the head. If the bear returns, repeat. Do not attempt to retrieve food or gear from a bear until it abandons the items.
