Smoke Management and Air Quality


When visiting Yosemite, it is possible to see fire and smoke at any time of the year. Beginning in fall through early spring, piles from mechanical thinning projects are often being burned in various areas throughout the park and along roadways. Spring, summer, and fall are all busy seasons for fire whether from prescribed fires, or managed wildfires. 

Where there is fire, there is smoke. During both prescribed fires and managed wildfires smoke and air quality conditions are consistently being monitored to help minimize smoke impacts. However, it is inevitable that some smoke will be present—whether on roadways, in campgrounds, or in areas that obscure vistas. If you are sensitive to smoke, you may consider visiting an area of Yosemite where fire or smoke is not present, and taking any other precautions that will help lessen smoke-related health problems. 

It is a unique and exciting opportunity to observe fire in the wilderness. If possible, Yosemite attempts to leave nearby roads and trails accessible during fire projects so that visitor services are not compromised. When conditions allow, this can be a great chance for people to learn more about natural fire firsthand.

Fire staff monitoring prescribed fire
Fire staff monitoring a prescribed fire.

Smoke Management

Fire managers are aware of the need for smoke management in order to reduce impacts to park visitors and neighboring communities. Yosemite Fire and Aviation works closely with park air quality managers to calculate how much smoke may be produced based on the vegetation (fuel) type, number of acres, and meteorlogical conditions. Portable and stationary particulate monitors are placed in areas that are most likely to see impacts of smoke during certain hours of the day. The local Air Quality Districts use the data from these monitors to issue air quality alerts and notices.

During times where smoke from a wildland fire is affecting the park, the local Air Quality District will send out alerts and notices. We work closely with local districts to maintain that conditions are within legal limits and not posing threats to people in nearby communities. Overall, we want you to have a positive experience visiting or living near Yosemite, while also learning about fire's important role in the ecosystem.

Allowing fires to burn naturally can result in a healthier, more diverse ecosystem. Reducing fuel buildup minimizes the potential for future catastrophic fires. Although the current fire may have transient, moderate smoke impacts, more severe fires can cause unhealthy levels of smoke for extended periods, over a much wider area.

If you have low tolerance for smoke, take these measures to reduce your exposure in places where smoke from wildland fire is occurring:

  • Stay indoors as much as possible, especially sensitive individuals and avoid physical exertion.

  • Close windows, doors, and outside vents when it is smoky. Use a fan or air conditioner to recirculate the air. Ventilate your home and work place during periods when it is least smoky.

  • Drink lots of water, eat a balanced diet, and get adequate rest. Good health strengthens your immune system.

  • Be diligent about taking medicines prescribed by your doctor, if you have pre-existing respiratory problems.

Learn more about air quality monitoring in Yosemite.

Smoke sitting in Yosemite Valley showing how the inversion layer can get during fires and campfires
Inversion layer of smoke in Yosemite Valley.

Yosemite Air Quality Monitoring

Fine particles/smoke at the Yosemite Valley Visitor's Center

The chart below plots both the 1-hour and running 24-hour average PM2.5 concentration, but only the 24-hour average should be used to compare with the standard. The standard is exceeded when the 24-hour concentrations go above 35 micrograms per cubic meter, as denoted by the line with the label NAT'L AMBIENT AIR QUALITY STANDARD. The background of the chart is color coded and relates to the EPA National Ambient Air Quality Standard for particulate matter, which is designed to protect human health.

10 day chart of fine particles at Yosemite Valley Visitor Center


Yosemite Webcams

Yosemite is always accessible to you! View current conditions from any of our five webcams.
Ahwahnee Meadow webcam, courtesy Yosemite Conservancy

Ahwahnee Meadow webcam in Yosemite Valley, looking east toward Half Dome
Sentinel Dome webcam, courtesy Yosemite Conservancy

High Sierra webcam at Sentinel Dome near Glacier Point, looking east out over the High Sierra
El Capitan (east) webcam, courtesy Yosemite Conservancy

El Capitan webcam at Turtleback Dome, looking east toward El Capitan and Half Dome
View west from Turtleback Dome

View of the Merced River Canyon, looking west from Yosemite Turtleback Dome Central Valley.
Yosemite Falls webcam, courtesy Yosemite Conservancy

Yosemite Falls Webcam looking north toward Yosemite Falls from the Lodge at Yosemite Falls

Yosemite Observer Dashboard: Air Quality


Visual, interactive information about current weather, stream flow, fires, and air quality conditions; all on one site! 


Campgrounds and Campfires

Yosemite has 13 campgrounds, each with many campsites, and therefore, many campfires. Emissions from many simultaneous campfires can degrade air quality on a local scale. This is especially true in the nighttime and early morning hours, when inversions trap and concentrate fine particles from those campfires near the ground, creating local conditions that are potentially unhealthy for sensitive individuals.

Campground Fire Prevention

Each year campfires, smoking, and human carelessness cause unwanted fires in Yosemite. You can help prevent these fires by following a few fire safety tips. Make sure to check with a Ranger if you are unsure.

Charcoal Briquettes

  • Never burn charcoal briquettes in a tent or vehicle.
  • After use, drown burning briquettes in water until cold. Carefully check them to make sure the fire is out.
  • Never throw burning briquettes into trash cans, dumpsters, forest, or surrounding vegetation.
  • Put extinguished briquettes into the fire pits provided at the campground.

Camping Stoves and Lanterns

  • Refuel stoves or lanterns only when they are cold and in a well ventilated area.
  • Never burn camp stoves and lanterns in a tent, vehicle, or other confined space.


  • Never throw lighted cigarettes on the ground or out of a car window. It is littering and could cause a wildfire.
  • Crush cigarette butts "dead out" before discarding in an ash tray or trash can.
  • Smoking while traveling on trails is prohibited. Persons who wish to smoke must stop and remain in one location until they have extinguished their smoking material.


  • Build small campfires in established campfire rings.
  • Clear all flammable vegetation at least 10 feet in all directions.
  • Never leave a campfire unattended.
  • Extinguish campfires thoroughly before you leave by using water, stirring with a tool, and feeling with the back of your hand. Do these steps over and over until the fire is completely cold and you can physically touch it.
  • Do not simply bury a fire in dirt, the fire will continue to smolder, spread underground, and surface later. It could also spread by the wind and cause a wildfire.
  • Do not burn toilet paper or trash!

Fireworks Are Illegal in Yosemite National Park

Last updated: August 21, 2023

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