Santa Ana winds
From Wikipedia, the free encyclopedia
This article is about the seasonal strong winds in Southern California. For other uses, see Santa Ana winds (disambiguation).
 The Santa Ana winds sweep down from the deserts and across coastal Southern California, pushing dust and smoke from wildfires far out over the Pacific Ocean. Los Angeles is in the upper left of this image, while San Diego is near the center. The Santa Ana winds, occasionally referred to as the devil winds, [1] [2] 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. [3] They often bring the lowest relative humidities of the year to coastal Southern California, and "beautifully clear skies". [4] These low humidities, combined with the warm, compressionally-heated air mass, plus high wind speeds, create critical fire weather conditions, and fan destructive wildfires. [4]
Typically, about 10 to 25 Santa Ana wind events occur annually. [5] A Santa Ana wind can blow from one to seven days, with an average wind event lasting three days. [6] The longest recorded Santa Ana event was a 14-day wind in November 1957. [5] Damage from high winds is most common along the Santa Ana River basin in Orange County, the Santa Clara River basin in Ventura and Los Angeles County, through Newhall Pass into the San Fernando Valley of Los Angeles County, and through the Cajon Pass into San Bernardino County near San Bernardino, Fontana, and Chino. [6]
The Santa Ana Winds drive most wildfires in Southern California. Most recently, the winds are known as the force behind the January 2025 Southern California wildfires.
---
Santa Ana winds often bring the lowest relative humidities of the year to coastal Southern California. These low humidities, combined with the warm, compressionally-heated air mass, plus the high wind speeds, create critical fire weather conditions. The combination of wind, heat, and dryness accompanying the Santa Ana winds turns the chaparral into explosive fuel feeding the infamous wildfires for which the region is known.
---
en.wikipedia.org
The Santa Ana winds and the accompanying raging wildfires have been a part of the ecosystem of the Los Angeles Basin for over 5,000 years, dating back to the earliest habitation of the region by the Tongva and Tataviam peoples. [22] The Santa Ana winds have been recognized and reported in English-language records as a weather phenomenon in Southern California since at least the mid-nineteenth century. [1] During the Mexican–American War, Commodore Robert Stockton reported that a "strange, dust-laden windstorm" arrived in the night while his troops were marching south through California in January 1847. |
