That's generally true anywhere, not just in California. It's called the "adiabatic lapse rate".
As you ascend the mountain the atmospheric temperature will decrease by about 6.5 degrees Celsius per 1 km (that is why the tops of high mountains have snow on them).
As elevation increases temperature decreases reaching the coldest altitude (around -90 degrees C). Once you ascend into the Thermosphere (56 miles high) The temperatures will be extremely high, ranging from 200 degrees C up to 500 Degrees C as you climb in elevation.
The Adirondack Mountains are located in the Northeast of Upstate New York. Their exact coordinates are 44 degrees North and 73 degrees West. The elevation is 5,344 feet.
5 degrees = Mount Snowdon
down to 64 degrees
about 60 degrees
Southern California!
-5 degrees Fahrenheit
70 degrees Fahrenheit
As elevation increases, the temperature typically decreases. This is because air pressure decreases with altitude, causing the air to expand and cool. The rate of temperature decrease with elevation is called the lapse rate.
In the troposphere, the temperature drops. In the stratosphere (layer above the troposphere) it increases with elevation. In the mesosphere, temperature drops again with elevation. In the theromosphere, it goes up again (to nearly stellar surface temperatures).
At 15,000 feet elevation, the air temperature can vary widely depending on multiple factors such as the time of day, season, and location. However, on average, the temperature at this elevation tends to be around 40-50 degrees Fahrenheit colder than at sea level.