Highway 166 reopened Wednesday morning after an overnight closure for several small vegetation fires along the roadway, according to authorities. 

Caltrans officials said the highway reopened as of 8:15 a.m. but fire crews remained on the scene mopping up. 

CalFire SLO responded to multiple vegetation fires along Highway 166 early Wednesday morning near Alamo Creek Road. The fires were reportedly burning less than an acre each, but one later grew to about 12 acres and prompted a larger firefighting response. 

The California Highway Patrol closed Highway 166 overnight between Highway 101 in Santa Maria and Perkins Road in New Cuyama because of the fires, and advised drivers to use alternate routes. 

The Highway 166 corridor, Cuyama Valley and other interior Santa Barbara County areas are under a heat advisory this week. New Cuyama is forecast to reach 104 degrees on Thursday, according to the National Weather Service. 

Coastal communities of the county will also have a warm week, but with high temperatures in the 80s and low 90s expected. 

Get the latest forecasts and weather-related alerts from the National Weather Service.