Australian and New Zealand firefighters are heading for the United States.
Their help was requested by the US National Interagency Fire Centre. Others have been requested from Canada and Mexico, making a total of more than 130 from outside the United States.
The ANZAC contingent will be there for five weeks. They were previously deployed in 2006.
Nine are going from New Zealand; 10 from NSW, nine from Victoria, eight from Western Australia, four from the ACT, three from Tasmania and one from South Australia.
California is the worst hit area.
The state has seen an outbreak of fires since 21 June. At one point there were more than 1,700 fires in central and northern parts of the state. Some 322 wildfires are still burning. So far, more than 2600 square km have been burned.
Other fires are burning in Arizona and Washington state.
About 20,000 personnel are already involved in fighting them.
California Governor Arnold Schwarzenegger has called up an extra 2000 National Guard troops.
Wildfires in California in October left eight people dead, destroyed 2000 homes and caused $US2 billion damage.