The Santa Ana winds, occasionally referred to as the devil winds, are strong, extremely dry katabatic winds that originate inland and affect coastal Southern California and northern Baja California. They originate from cool, dry high-pressure air masses in the Great Basin.
Santa Ana winds are known for the hot, dry weather that they bring in autumn (often the hottest of the year), but they can also arise at other times of the year. They often bring the lowest relative humidities of the year to coastal Southern California, and "beautifully clear skies". These low humidities, combined with the warm, compressionally heated air mass and high wind speeds, create critical fire weather conditions that fan destructive wildfires.