Diablo wind

The air descending from aloft as well as from the Coast Ranges compresses as it sinks to sea level where it warms as much as 20 °F (11 °C), and loses relative humidity.

This is the reverse of the normal summertime weather pattern in which an area of low pressure (called the California Thermal Low) rather than high pressure lies east of the Bay Area, drawing in cooler, more humid air from the ocean.

This effect is especially dangerous with respect to wildfires as it can enhance the updraft generated by the heat in such fires.

[7] Effects tend to be halved at farther southern coasts, and even can spawn Sundowner winds in Santa Barbara.

Southern Californian coasts from Ventura County south are generally unaffected by Diablo events.