Photo: BC Wildfire Service

Fire southwest of La la Hache on Sunday.

The first heat wave of the summer is expected to hit B.C.'s Cariboo region by the weekend, and the BC Wildfire Service says it is bracing for potential fires.

The service says lightning storms along with the heat could spawn increased wildfire activity across the Central Interior.

It says there were three lightning-caused fires in the region over the last four days after seeing just seven between April 1 and June 20.

Thirty-four other wildfires over that period were blamed on human activity.

The fire danger rating in the area covered by the Cariboo fire centre is mostly moderate to high, although an extreme fire risk is posted across much of the Chilcotin fire zone, which is within the centre.

Environment Canada forecasts temperatures in Williams Lake could reach 30 C by Sunday.