Gusty conditions have enabled fires to take hold and spread at great speed. Plus, a cold snap grips South Korea

• LA wildfires: what we know so far
• LA fires live updates: California wildfires latest news

The rapid spread of one of the most destructive wildfires in the history of Los Angeles is believed to have been fuelled by strong Santa Ana winds and months of drought.

Santa Ana winds occur between September and May, when high pressure over the deserts of the south-western US and low pressure off the coast of California allow winds to flow east to west, through mountain passages in California towards the ocean. This week, a strong Santa Ana event brought gusts of 100mph (160km/h) to Los Angeles.