If you've been enjoying a relatively cooler summer so far, things are about to heat up. The National Weather Service is forecasting triple digit temperatures in Sacramento and the Central Valley this weekend, the hottest so far this summer. Temperatures could hit up to 110 degrees in some areas beginning Friday due to what's called a heat dome. With high temperatures and low humidity in the single digits, Spender says there will be an elevated fire concern. "If we break down the ridge, that's when we start to return to more seasonal temperatures," says Spender.