The Foreign and Commonwealth Office (FCO) is still warning British tourist traveling to California of the dangers despite reports of fires subsiding.
Travelers are warned that air quality is poor and telephones are extremely busy, particularly in the San Diego area.
The FCO said: "Residents and tourists should heed warnings from the local Sheriff's and/or Fire Department on when to evacuate and take their advice on where to evacuate."
"Callers may experience difficulty in placing calls to the area," it added.
The FCO estimates that around 6.5 million Brits travel to the USA every year, where bush fires are currently raging across the state of California.
According to the BBC, around 1,596 homes have been destroyed and one million people have been evacuated, with 20 injured and three killed.
In light of the disaster, airlines including Continental Airlines and American Airlines have waived fees for changing flights in around 12 cities in the California area.
