The climate is Mediterranean with cool to cold, wet, in some cases snowy winters and dry, hot summers. Usually the areas north of Interstate 210 and east of Interstate 215 see colder weather in the winter with occasional snowfall. Sage scrub and the Yucca plant are the predominant natural vegetation along washes and uplands; it intergrades with chaparral at elevations of 600 to 700 meters. Other vegetation consists of a patchwork of grasslands, riparian woodlands, and mixed hardwood forests, which border the valley in the mountains on the north and east. The Santa Ana winds blow into the valley from the Cajon Pass, which exits the valley's north end between the San Gabriel and San Bernardino mountains.