When a fire is burning in Yosemite National Park, the park 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 meteorological conditions. Portable and stationary particulate monitors are placed in areas that are most likely to see impacts of smoke. Local air quality districts use 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(s) will send out alerts and notices.
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. As of August 15, 2017, two significant fires are burning in the park. The Empire Fire is a lightning-ignited fire being managed for resource benefit. The larger smoke producer, the South Fork Fire, is being suppressed.
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 if you're sensitive to smoke, and avoid physical exertion.
- Close windows, doors, and outside vents when it is smoky. Use a fan or air conditioner to re-circulate 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.