The regional office of the Emergency Situations Ministry said the number of fires grew to 43 from 28 in 24 hours, ITAR-Tass reported. The areas most at risk are the heavily forested Altai Republic and the Trans-Baikal region, both on Russia's southern border.
The ministry has deployed 755 firefighters and 188 vehicles.
A spokesman for the regional office said the situation is being closely watched in case the fires spread toward inhabited areas.
Last year, in a summer of record-breaking heat, hundreds of forest fires, mostly in western Russia, killed hundreds of people and destroyed entire villages. Public health officials estimated 56,000 people died as a result of the smog that blanketed Moscow and other large cities or from the heat.