Santa Ana winds (SAWs) are associated with anomalous temperatures in coastal Southern California (SoCal). As dry air flows over SoCal’s coastal ranges on its way from the elevated Great Basin down to sea level, all SAWs warm adiabatically. Many but not all SAWs produce coastal heat events. The strongest regionally averaged SAWs tend to be cold. In fact, some of the hottest and coldest observed temperatures in coastal SoCal are linked to SAWs. We show that hot and cold SAWs are produced by distinct synoptic dynamics. High-amplitude anticyclonic flow around a blocking high pressure aloft anchored at the California coast produces hot SAWs. Cold SAWs result from anticyclonic Rossby wave breaking over the northwestern U.S. Hot SAWs are preceded by warming in the Great Basin and dry conditions across the Southwestern U.S. Precipitation over the Southwest, including SoCal, and snow accumulation in the Great Basin usually precede cold SAWs. Both SAW flavors, but especially the hot SAWs, yield low relative humidity at the coast. Although cold SAWs tend to be associated with the strongest winds, hot SAWs tend to last longer and preferentially favor wildfire growth. Historically, out of large (> 100 acres) SAW-spread wildfires, 90% were associated with hot SAWs, accounting for 95% of burned area. As health impacts of SAW-driven coastal fall, winter and spring heat waves and impacts of smoke from wildfires have been recently identified, our results have implications for designing early warning systems. The long-term warming trend in coastal temperatures associated with SAWs is focused on January–March, when hot and cold SAW frequency and temperature intensity have been increasing and decreasing, respectively, over our 71-year record.

圣安娜风 (SAW) 与南加州沿海 (SoCal) 的异常温度有关。当干燥的空气在从高架的大盆地下降到海平面的途中流过 SoCal 的沿海山脉时，所有的 SAW 都在绝热地变暖。许多但不是所有的 SAW 都会产生沿海高温事件。最强的区域平均 SAW 往往是冷的。事实上，在 SoCal 沿海地区观测到的一些最热和最冷的温度与 SAW 有关。我们表明，冷热 SAW 是由不同的天气动力学产生的。在加利福尼亚海岸锚定的高空阻塞高压周围的高振幅反气旋流产生热 SAW。冷 SAW 是由反气旋罗斯比波在美国西北部突破造成的 热 SAW 之前是大盆地变暖和美国西南部干旱 西南地区（包括南加州）的降水和大盆地的积雪通常先于冷 SAW。两种 SAW 口味，尤其是热 SAW，在海岸产生的相对湿度较低。尽管冷 SAW 往往与最强风有关，但热 SAW 往往持续时间更长，并且优先有利于野火的生长。从历史上看，在大型（> 100 英亩）SAW 蔓延的野火中，90% 与热 SAW 有关，占烧毁面积的 95%。由于最近发现了 SAW 驱动的沿海秋季、冬季和春季热浪对健康的影响以及野火产生的烟雾的影响，我们的结果对设计早期预警系统具有重要意义。与 SAW 相关的沿海温度的长期变暖趋势集中在 1 月至 3 月，