Forecasts indicate the park can expect unhealthy air quality for the next several days. Park officials said in a news release they anticipate Yosemite will be closed "at least throughout the weekend," but did not provide an exact time for reopening.
The park is expected to reopen when conditions improve.
Sequoia and Kings Canyon National Parks and surrounding national forests are also closed due to fire activity.
According to AirNow, sensors showed Yosemite National Park with an air quality index of 733 Thursday afternoon. Anything higher than 151 is considered unhealthy for most people.
The park reopened in early June with many restrictions after shutting down in March due to the COVID-19 pandemic.