Nearly 170,000 hectares of forestland is burning in the Krasnoyarsk, Irkutsk, Yakutia, Yamal, and Buryatia regions, TASS reported, citing the Aerial Forest Protection Service.
The hygienic standard in the air exceeds the norm by 1.2 to 2.3 times, The Siberian Times reported, citing state-run consumer watchdog Rospotrebnadzor.
More than 2,000 people and 303 units of equipment are involved in extinguishing the existing 171 fires.
Thirty-five wildfires were extinguished over an area of 17,600 hectares in the last 24 hours.
The regional government of Krasnoyarsk, where most of the blazes are, blamed lightning for starting most of the fires.
Residents in Krasnoyarsk have been told to go outdoors only out of necessity.
Pollution from the wildfires has spread to other geographic regions.