County firefighters stopped the forward progress and put out the flames of the Post Fire Sunday, a brush fire near the 5 Freeway in Gorman that charred approximately 200 acres and was 20% contained.
Smoke could be seen for several miles and active flames were burning alongside the freeway.
The California Highway Patrol issued a SigAlert in Castaic at 8:09 p.m. The northbound 5 was closed at Smokey Bear Road and the transition road between westbound state Route 138 and northbound 5 was also shut down, the CHP said. Northbound lanes 1 and 2 were reopened at 11:08 p.m.
There were no immediate reports of injuries or burning structures.
This year's fire season has already seen above normal activity. A dry winter, followed by a hot spring created favorable conditions for fires and rapid spread, according to the The National Significant Wildland Fire Potential Outlook issued in July. In August and September, above normal temperatures along with drought conditions are expected to lead to an expansion of wildfires in parts of California, the report said.
So far this year, CALFIRE has reported more than 4,460 wildfires that burned nearly 60,000 acres in California. During that same period last year, the agency reported 2,678 fires that a burned more than 22,700 acres. The five-year average for that timespan is 3,037 fires and 95,585 acres.
